Does anyone else find GM strut design annoying?
manicmechanix
05-13-2009, 05:34 PM
On GM struts the lower mount typically has two bolts that clamp the strut to the knuckle. These bolts are splined and are a slight press fit into the knuckle. This is all right because it accurately locates the the strut/knuckle interface (and camber alignment) and keeps the bolts from turning once the bolt splines are pushed into the strut and knuckle and engaging. Now, on the factory orignal the bottom stut hole is punched or honed out for the bolt (Not elongated which I'll get to later). Maybe they place this hole precisely to get best camber alignment on each assembly, or maybe they just place it in the center and it's not placed specific for the assembly, I'm not sure. So far so good.
Now I'll get to the annoying and impractical parts. Any service procedure will tell you to scribe mark the strut before disassembly to get the same alignment. Well this would seem unnecessary with the original strut because the hole only locates in one position and isn't elongated. Maybe this is just in case the original was replaced sense a replacement strut will have the bottom strut hole elongated. I never seen a service procedure make this distinction though.
The thing is, is it not even practical to adjust where the bottom bolt mounts through the strut or to alining it to match marks? I don't know of anyone that does this or readjust the Camber on GM strut suspensions. If you replace the strut it will have an elongated hole, so now the camber will be most likely moved. It would seem pretty difficult and impractical to loosen both the strut bolts knock them out and turn the strut in relation to the knuckle to an alignment spec and then tap the strut bolts in all without moving anything.
Why don't they just have a fixed bottom hole since is seems so impractical to adjust the camber that way anyway? it'd make things a lot simpler.
Now I'll get to the annoying and impractical parts. Any service procedure will tell you to scribe mark the strut before disassembly to get the same alignment. Well this would seem unnecessary with the original strut because the hole only locates in one position and isn't elongated. Maybe this is just in case the original was replaced sense a replacement strut will have the bottom strut hole elongated. I never seen a service procedure make this distinction though.
The thing is, is it not even practical to adjust where the bottom bolt mounts through the strut or to alining it to match marks? I don't know of anyone that does this or readjust the Camber on GM strut suspensions. If you replace the strut it will have an elongated hole, so now the camber will be most likely moved. It would seem pretty difficult and impractical to loosen both the strut bolts knock them out and turn the strut in relation to the knuckle to an alignment spec and then tap the strut bolts in all without moving anything.
Why don't they just have a fixed bottom hole since is seems so impractical to adjust the camber that way anyway? it'd make things a lot simpler.
J-Ri
05-13-2009, 09:14 PM
I think you're right about the reason for scribing the location, for almost any "service procedure", I can tell you a couple steps that are entirely unnecessary (drain the coolant, then remove the lower radiator hose... the second tends to take care of the first :)).
From what I've seen, GM has some of the best struts overall. Look up the camber/caster procedure for a Windstar if you doubt that :rolleyes:. All Fords have the same rediculous "slot the strut mount holes", but for the Windstar you have to remove all the plastic over the struts. I'd like to see those strut towers after a few alignments, might be better to drill out the holes to 1/2" :eek7:
I can do the camber in about 5 minutes on each side on GM struts (once the vehicle is set up on the rack). What I do first, while it's still on my hoist, is put my impact on both bolts and spin the them so the splines chew out the metal, leave them just snug and then drive it over to the alignment rack. The machine we have has "jacking compensation" which means you can raise the wheels of either or both axles just off the turn plates and you can easily move the camber to exactly where you want it, and the computer compares the before and after jacking angles so it tells you exactly the angle (to .1 degrees) even with the wheels jacked. Once I have the camber where I want it, I have a helper snug the bolts while I'm still holding the wheel in the right place (or if nobody has any time to help, I'll just leave the top bolt snug and tap the wheel with a plastic hammer). The reason they have the bottom hole slotted on the repalcement strut is that any time you replace struts you need to align it, the slot just makes it easier to do it properly. It can be much further off with the slots if you do it the quick way, but every replacement strut alters the alignment a few tenths of a degree which usually makes the car dirve a bit off. I have seen some that the camber and caster are both off but cancel eachother's tendancy to pull. After replacing suspension components, I'd say less than 20% are even within the tolerance range, and even half of the tolerance can make it pull quite a bit depending on what's off and in which direction.
From what I've seen, GM has some of the best struts overall. Look up the camber/caster procedure for a Windstar if you doubt that :rolleyes:. All Fords have the same rediculous "slot the strut mount holes", but for the Windstar you have to remove all the plastic over the struts. I'd like to see those strut towers after a few alignments, might be better to drill out the holes to 1/2" :eek7:
I can do the camber in about 5 minutes on each side on GM struts (once the vehicle is set up on the rack). What I do first, while it's still on my hoist, is put my impact on both bolts and spin the them so the splines chew out the metal, leave them just snug and then drive it over to the alignment rack. The machine we have has "jacking compensation" which means you can raise the wheels of either or both axles just off the turn plates and you can easily move the camber to exactly where you want it, and the computer compares the before and after jacking angles so it tells you exactly the angle (to .1 degrees) even with the wheels jacked. Once I have the camber where I want it, I have a helper snug the bolts while I'm still holding the wheel in the right place (or if nobody has any time to help, I'll just leave the top bolt snug and tap the wheel with a plastic hammer). The reason they have the bottom hole slotted on the repalcement strut is that any time you replace struts you need to align it, the slot just makes it easier to do it properly. It can be much further off with the slots if you do it the quick way, but every replacement strut alters the alignment a few tenths of a degree which usually makes the car dirve a bit off. I have seen some that the camber and caster are both off but cancel eachother's tendancy to pull. After replacing suspension components, I'd say less than 20% are even within the tolerance range, and even half of the tolerance can make it pull quite a bit depending on what's off and in which direction.
manicmechanix
05-13-2009, 10:04 PM
I think the GM design is pretty good. I just think they could've drilled the holes for the strut bolts so the replacement strut would be Camber "neutral" in dimension like the originals are and leave it at that.
That's interesting with the jacking plates. So do they lift and lower at the tires and allow you to add or remove camber? This would make knuckle move within the strut once the bolts are loosened which is about impossible to do by hand. Seems like it would be tricky to get access to the strut bolts to loosen and then tighten them with the tire still on though.
That must be some impact you have that will spin the bolts and chew out the knuckle with the bolt splines. I don't mean to question how you do it, but the splines and interference fit are some of the pluses of the GM design-the bolt and the camber can't move with the splines and interference fit. Say you have a replacement strut with the bottom hole already elongated (For the originals the factory service material says to take the strut off and elongate the bottom hole, yeah right) why not just tap the original bolts out, shift the camber, then tap them back in and tighten? Would it be hard to access them with the wheels on and on the alignment rack?
I also understand there are aftermarket eccentric bolts that allow you to adjust the camber. But they have the problem of being smaller and weaker than the original bolt and the camber can move. I just think GM should've either put a wel ldesigned eccentric bolton the strut to adjust camber or just made the holes at a standard unadjustable neutral dimension.
That's interesting with the jacking plates. So do they lift and lower at the tires and allow you to add or remove camber? This would make knuckle move within the strut once the bolts are loosened which is about impossible to do by hand. Seems like it would be tricky to get access to the strut bolts to loosen and then tighten them with the tire still on though.
That must be some impact you have that will spin the bolts and chew out the knuckle with the bolt splines. I don't mean to question how you do it, but the splines and interference fit are some of the pluses of the GM design-the bolt and the camber can't move with the splines and interference fit. Say you have a replacement strut with the bottom hole already elongated (For the originals the factory service material says to take the strut off and elongate the bottom hole, yeah right) why not just tap the original bolts out, shift the camber, then tap them back in and tighten? Would it be hard to access them with the wheels on and on the alignment rack?
I also understand there are aftermarket eccentric bolts that allow you to adjust the camber. But they have the problem of being smaller and weaker than the original bolt and the camber can move. I just think GM should've either put a wel ldesigned eccentric bolton the strut to adjust camber or just made the holes at a standard unadjustable neutral dimension.
J-Ri
05-14-2009, 08:04 PM
I think the GM design is pretty good. I just think they could've drilled the holes for the strut bolts so the replacement strut would be Camber "neutral" in dimension like the originals are and leave it at that.
That's interesting with the jacking plates. So do they lift and lower at the tires and allow you to add or remove camber? This would make knuckle move within the strut once the bolts are loosened which is about impossible to do by hand. Seems like it would be tricky to get access to the strut bolts to loosen and then tighten them with the tire still on though.
That must be some impact you have that will spin the bolts and chew out the knuckle with the bolt splines. I don't mean to question how you do it, but the splines and interference fit are some of the pluses of the GM design-the bolt and the camber can't move with the splines and interference fit. Say you have a replacement strut with the bottom hole already elongated (For the originals the factory service material says to take the strut off and elongate the bottom hole, yeah right) why not just tap the original bolts out, shift the camber, then tap them back in and tighten? Would it be hard to access them with the wheels on and on the alignment rack?
I also understand there are aftermarket eccentric bolts that allow you to adjust the camber. But they have the problem of being smaller and weaker than the original bolt and the camber can move. I just think GM should've either put a well designed eccentric bolt on the strut to adjust camber or just made the holes at a standard unadjustable neutral dimension.
I know what you mean about having a non-adjustable strut being easier to just swap out (like Fords), but when you get something bent slightly it's a PITA to remove the strut mount from the tower, grind the holes out oblong, put the strut back in, tighten the nuts, find out that tightening the nuts twisted the strut a little bit, loosen them back up, and so on...
The alignment rack is two parallel tracks, kind of like a car trailer (just wider and sturdier, about 3' between the insides with about 2' wide tracks and made of 1/4" steel). The whole thing raises up about 6' off the ground for easy access to underneath the car. Between the two tracks are rails with rolling jacks on them that pivot from horizontal to vertical and are the same thickness as the tracks, so it goes all the way to the floor and the car only needs about 1" ground clearance to drive on the rack, but getting it up the ramp would be a challenge without a whole lumber yard full of 2x4 "bridges" :eek:. When the jacks are pivoted to the vertical position, they'll reach the frame on just about any vehicle (the arms slide out once locked in the vertical position and will reach to the pinch weld on most cars if there's no subframe). The biggest one we've had so far was a 3/4 ton Dodge Ram, and it could have had a couple inches and still had the jacks reach. I have an impact set of 1/2" drive extensions and a 1/2" impact U-joint socket that makes it pretty easy to get to the bolts with the wheel on.
My big impact is the Snap-On IM6500 which has 650 ft lbs reverse torque and I think 600 forward. I only remember the 650 because it's etched into the side :). If it doesn't break a nut/bolt loose, it will usually snap 3/8" and smaller bolts if I keep going at it... nice sometimes rather than grinding/drilling. I know what you mean about the plusses of the splines and the interference fit, but really all I'm doing by removing the splines is changing that interference fit to a zero-tolerance fit. The thing is, once you have the replacement strut on there, the bottom bolt doesn't grip anything on the strut anyway. You hit it right on the head (so to speak), getting a hammer up in there would be much harder than an extension. The few I did try that way the splines were long enough that I had to back them out (really hard with a punch up in there) to where the end of the bolt wasn't through the strut anymore, which meant I had to wiggle the strut to get it through which screwed up the camber. It's easier to just shear the splines off, and I have never had one come back. If I ever do then of course I'll stop doing it that way, but so far so good. There's so much static friction between the strut and the steering knuckle that I don't see it moving at all with those bolts tight.
I agree completely about having a well designed eccentric bolt in there from the factory. I got a set of camber bolts for my car because it still has the factory struts on there, I'm thinking about not using them and just replacing the struts (no way am I elongating the holes)... the way I drive, I'm sure I'll knock the camber off sooner or later. I didn't realize just how much smaller they are until I got them, Cavaliers have tiny bolts anyway, but these are way too small IMO.
EDIT: Did a quick search, this is our rack, a picture's worth 1000 words http://www.hunter.com/pub/product/racks/4718T/index.htm
That's interesting with the jacking plates. So do they lift and lower at the tires and allow you to add or remove camber? This would make knuckle move within the strut once the bolts are loosened which is about impossible to do by hand. Seems like it would be tricky to get access to the strut bolts to loosen and then tighten them with the tire still on though.
That must be some impact you have that will spin the bolts and chew out the knuckle with the bolt splines. I don't mean to question how you do it, but the splines and interference fit are some of the pluses of the GM design-the bolt and the camber can't move with the splines and interference fit. Say you have a replacement strut with the bottom hole already elongated (For the originals the factory service material says to take the strut off and elongate the bottom hole, yeah right) why not just tap the original bolts out, shift the camber, then tap them back in and tighten? Would it be hard to access them with the wheels on and on the alignment rack?
I also understand there are aftermarket eccentric bolts that allow you to adjust the camber. But they have the problem of being smaller and weaker than the original bolt and the camber can move. I just think GM should've either put a well designed eccentric bolt on the strut to adjust camber or just made the holes at a standard unadjustable neutral dimension.
I know what you mean about having a non-adjustable strut being easier to just swap out (like Fords), but when you get something bent slightly it's a PITA to remove the strut mount from the tower, grind the holes out oblong, put the strut back in, tighten the nuts, find out that tightening the nuts twisted the strut a little bit, loosen them back up, and so on...
The alignment rack is two parallel tracks, kind of like a car trailer (just wider and sturdier, about 3' between the insides with about 2' wide tracks and made of 1/4" steel). The whole thing raises up about 6' off the ground for easy access to underneath the car. Between the two tracks are rails with rolling jacks on them that pivot from horizontal to vertical and are the same thickness as the tracks, so it goes all the way to the floor and the car only needs about 1" ground clearance to drive on the rack, but getting it up the ramp would be a challenge without a whole lumber yard full of 2x4 "bridges" :eek:. When the jacks are pivoted to the vertical position, they'll reach the frame on just about any vehicle (the arms slide out once locked in the vertical position and will reach to the pinch weld on most cars if there's no subframe). The biggest one we've had so far was a 3/4 ton Dodge Ram, and it could have had a couple inches and still had the jacks reach. I have an impact set of 1/2" drive extensions and a 1/2" impact U-joint socket that makes it pretty easy to get to the bolts with the wheel on.
My big impact is the Snap-On IM6500 which has 650 ft lbs reverse torque and I think 600 forward. I only remember the 650 because it's etched into the side :). If it doesn't break a nut/bolt loose, it will usually snap 3/8" and smaller bolts if I keep going at it... nice sometimes rather than grinding/drilling. I know what you mean about the plusses of the splines and the interference fit, but really all I'm doing by removing the splines is changing that interference fit to a zero-tolerance fit. The thing is, once you have the replacement strut on there, the bottom bolt doesn't grip anything on the strut anyway. You hit it right on the head (so to speak), getting a hammer up in there would be much harder than an extension. The few I did try that way the splines were long enough that I had to back them out (really hard with a punch up in there) to where the end of the bolt wasn't through the strut anymore, which meant I had to wiggle the strut to get it through which screwed up the camber. It's easier to just shear the splines off, and I have never had one come back. If I ever do then of course I'll stop doing it that way, but so far so good. There's so much static friction between the strut and the steering knuckle that I don't see it moving at all with those bolts tight.
I agree completely about having a well designed eccentric bolt in there from the factory. I got a set of camber bolts for my car because it still has the factory struts on there, I'm thinking about not using them and just replacing the struts (no way am I elongating the holes)... the way I drive, I'm sure I'll knock the camber off sooner or later. I didn't realize just how much smaller they are until I got them, Cavaliers have tiny bolts anyway, but these are way too small IMO.
EDIT: Did a quick search, this is our rack, a picture's worth 1000 words http://www.hunter.com/pub/product/racks/4718T/index.htm
manicmechanix
05-14-2009, 09:26 PM
OK good info J-ri, that makes things clearer. You can tell that I haven't ever used an alignment rack much :icon16:. I did want to mention that the GM W-body 88-9x Grand Prix, Cutlass etc, has the struts that come out through the top and the strut tube is fastened permanently to the knuckle and you have to elongated the strut tower holes to change the camber. I can see what you're saying that would be a pain in the butt.
On the two bolt design, I guess my thinking is you would have to take off the original to elongated the strut hole, so if it's bent, why not just replace it. And if the Camber is still off with a new adjustable strut then something is bent that needs replaced, But I can see how adjusting the strut to make up for something slightly wornm or bent is way easier and cheaper than chasing down the out of spec component.
I also agree that the strut is probably not going to move with all the clamping it has, but with the splines I agree the elongnated bottom may not be grabbing as tight but the unalter top one would still be. I think on my own personal car I would want to retain the original bolts and splines just to be original, but on cars that were coming in for alignment I think that's a different store. They're not paying enough money for perfection. I guess were in agreement that GM should've just put an easy to adjust and well designed eccentric bolt there.
I did have one question about spinning the strut-to-knuckle bolts with an impact. The bolt side is where the splines are and it has a 2-sided head instead of a regular socket hex. What kind of socket do you use? Also I have an almost new Ingersol Rand 2132G impact that should have at least 600ft lbs and it sometimes won't break bolts loose and probably would not spin those bolts splines off. I don't know what the problem with it is, maybe my compressor output volume is a little too low.
On the two bolt design, I guess my thinking is you would have to take off the original to elongated the strut hole, so if it's bent, why not just replace it. And if the Camber is still off with a new adjustable strut then something is bent that needs replaced, But I can see how adjusting the strut to make up for something slightly wornm or bent is way easier and cheaper than chasing down the out of spec component.
I also agree that the strut is probably not going to move with all the clamping it has, but with the splines I agree the elongnated bottom may not be grabbing as tight but the unalter top one would still be. I think on my own personal car I would want to retain the original bolts and splines just to be original, but on cars that were coming in for alignment I think that's a different store. They're not paying enough money for perfection. I guess were in agreement that GM should've just put an easy to adjust and well designed eccentric bolt there.
I did have one question about spinning the strut-to-knuckle bolts with an impact. The bolt side is where the splines are and it has a 2-sided head instead of a regular socket hex. What kind of socket do you use? Also I have an almost new Ingersol Rand 2132G impact that should have at least 600ft lbs and it sometimes won't break bolts loose and probably would not spin those bolts splines off. I don't know what the problem with it is, maybe my compressor output volume is a little too low.
J-Ri
05-14-2009, 11:07 PM
I have seen those struts before, "cartridge struts", you have to cut the weld and weld a new strut in to replace it. I/we won't mess with them! I only had to align one car that I had to elongate the strut tower holes for, and that was an assignment while I was in school. Definitely not the best way.
The thing is, even a degree or two on one side will make it pull quite a bit, if the car has 4k miles on it and the owner hit a curb pretty hard, it could easily make it pull, but the strut is probably still good. Just today I aligned a Chrysler 300, the camber was off by -.8 degrees and the caster off by +1.1 degrees on the right side... it pulled quite a bit. And guess what the recommended alignment procedure is? They say to loosen the engine cradle and move it to get the camber/caster :rolleyes: They do make adjustment bolts, but moving the f****** engine cradle is the preferred method.:banghead:
You sure got me thinking on those two sided heads... I'm sure that by the time I get a car on the alignment rack that I'm able to turn the bolt by hand with a wrench if I choose. Do the splines bite into the knuckle or just the strut? I wonder if maybe the replacement struts we get have larger holes? While they do make sockets for those bolts, I don't have them. I tend to look only at what I'm working on, it's possible I may be thinking of Toyota cars which I know for a fact have hex-head bolts, and the front suspension is surprisingly similar. Are you sure that all GMs with that design have two sided bolts? I sure think I've done that on them, but you've got me to thinking I do that on something else... I just go,go,go... at the end of a busy day I couldn't tell you what the make of that day's first car was. My mind's razor sharp on some things, but on other things... CRS A co-worker got me pretty good by walking up to me holding a pushrod while I was just finsihing up a 3.1l lower intake. I was sure I would have put them all back in, but I sure don't remember it :rofl:, he told me he was joking around before I took anything back off... but he sure had me on that! The next time I have the struts off one I'll try to remember to pay attention and I'll post back with what I do.
My impact is rated that torque @ 90 PSI, our shop air compressor kicks on at 150 PSI and the regulator's set to 175 PSI, so I'm sure that adds at least 50% to the output :)
The thing is, even a degree or two on one side will make it pull quite a bit, if the car has 4k miles on it and the owner hit a curb pretty hard, it could easily make it pull, but the strut is probably still good. Just today I aligned a Chrysler 300, the camber was off by -.8 degrees and the caster off by +1.1 degrees on the right side... it pulled quite a bit. And guess what the recommended alignment procedure is? They say to loosen the engine cradle and move it to get the camber/caster :rolleyes: They do make adjustment bolts, but moving the f****** engine cradle is the preferred method.:banghead:
You sure got me thinking on those two sided heads... I'm sure that by the time I get a car on the alignment rack that I'm able to turn the bolt by hand with a wrench if I choose. Do the splines bite into the knuckle or just the strut? I wonder if maybe the replacement struts we get have larger holes? While they do make sockets for those bolts, I don't have them. I tend to look only at what I'm working on, it's possible I may be thinking of Toyota cars which I know for a fact have hex-head bolts, and the front suspension is surprisingly similar. Are you sure that all GMs with that design have two sided bolts? I sure think I've done that on them, but you've got me to thinking I do that on something else... I just go,go,go... at the end of a busy day I couldn't tell you what the make of that day's first car was. My mind's razor sharp on some things, but on other things... CRS A co-worker got me pretty good by walking up to me holding a pushrod while I was just finsihing up a 3.1l lower intake. I was sure I would have put them all back in, but I sure don't remember it :rofl:, he told me he was joking around before I took anything back off... but he sure had me on that! The next time I have the struts off one I'll try to remember to pay attention and I'll post back with what I do.
My impact is rated that torque @ 90 PSI, our shop air compressor kicks on at 150 PSI and the regulator's set to 175 PSI, so I'm sure that adds at least 50% to the output :)
manicmechanix
05-15-2009, 01:39 AM
I have seen those struts before, "cartridge struts", you have to cut the weld and weld a new strut in to replace it. I/we won't mess with them! I only had to align one car that I had to elongate the strut tower holes for, and that was an assignment while I was in school. Definitely not the best way.
On those W-body cartridge struts, the '88 first year wasn't replaceable without cutting and welding but after 88 the strut cartridge will unbolt through the strut tower. If you have the strut tool set and do one of these it's easier than a regular strut. You should try it, you'd probably like doing them :). That W-body set up requires elongated the strut tower holes to adjust camber though. My feeling is the facotry should've elongnated the bolts if that's what's necessary to adjust camber.
The thing is, even a degree or two on one side will make it pull quite a bit, if the car has 4k miles on it and the owner hit a curb pretty hard, it could easily make it pull, but the strut is probably still good. Just today I aligned a Chrysler 300, the camber was off by -.8 degrees and the caster off by +1.1 degrees on the right side... it pulled quite a bit. And guess what the recommended alignment procedure is? They say to loosen the engine cradle and move it to get the camber/caster :rolleyes: They do make adjustment bolts, but moving the f****** engine cradle is the preferred method.:banghead:
This is interesting stuff. Even less than a degree of caster can cause a strong pull. Might experience is that if a car hits a curb it's usually the strut being the weak link that gets bent first and sometime they will bind after being bent too. If it was my car I would replace the strut. Moving the engine cradle just seems crazy since you'd be moving so many other things' positions along with it. Deos the 300M have struts or a upper and lower control arms. I know some Chryslers have upper control arms, I'm not sure which ones.
You sure got me thinking on those two sided heads... I'm sure that by the time I get a car on the alignment rack that I'm able to turn the bolt by hand with a wrench if I choose. Do the splines bite into the knuckle or just the strut? I wonder if maybe the replacement struts we get have larger holes? While they do make sockets for those bolts, I don't have them. I tend to look only at what I'm working on, it's possible I may be thinking of Toyota cars which I know for a fact have hex-head bolts, and the front suspension is surprisingly similar. Are you sure that all GMs with that design have two sided bolts? I sure think I've done that on them, but you've got me to thinking I do that on something else... I just go,go,go... at the end of a busy day I couldn't tell you what the make of that day's first car was. My mind's razor sharp on some things, but on other things... CRS A co-worker got me pretty good by walking up to me holding a pushrod while I was just finsihing up a 3.1l lower intake. I was sure I would have put them all back in, but I sure don't remember it :rofl:, he told me he was joking around before I took anything back off... but he sure had me on that! The next time I have the struts off one I'll try to remember to pay attention and I'll post back with what I do.
That's understandable, I forget things all the time. All the GM strut bolts I've seen had the two-sided bolt heads but I can't say they all do. Maybe Chryslers have hex heads. On the GM strut there's like an inner metal part with "teeth" that grab the knuckle. I think the splines grab on the inner layer of the strut and the knuckle as well.
My impact is rated that torque @ 90 PSI, our shop air compressor kicks on at 150 PSI and the regulator's set to 175 PSI, so I'm sure that adds at least 50% to the output :)
Yeah you got the full sized 2-stage compressor :icon16:. But did you mean the compressor tank is set to 175 psi or the regulator to your impact 175 psi too and not 90 psi? I only run 90 psi because I'd think higher would damage my impact.
On those W-body cartridge struts, the '88 first year wasn't replaceable without cutting and welding but after 88 the strut cartridge will unbolt through the strut tower. If you have the strut tool set and do one of these it's easier than a regular strut. You should try it, you'd probably like doing them :). That W-body set up requires elongated the strut tower holes to adjust camber though. My feeling is the facotry should've elongnated the bolts if that's what's necessary to adjust camber.
The thing is, even a degree or two on one side will make it pull quite a bit, if the car has 4k miles on it and the owner hit a curb pretty hard, it could easily make it pull, but the strut is probably still good. Just today I aligned a Chrysler 300, the camber was off by -.8 degrees and the caster off by +1.1 degrees on the right side... it pulled quite a bit. And guess what the recommended alignment procedure is? They say to loosen the engine cradle and move it to get the camber/caster :rolleyes: They do make adjustment bolts, but moving the f****** engine cradle is the preferred method.:banghead:
This is interesting stuff. Even less than a degree of caster can cause a strong pull. Might experience is that if a car hits a curb it's usually the strut being the weak link that gets bent first and sometime they will bind after being bent too. If it was my car I would replace the strut. Moving the engine cradle just seems crazy since you'd be moving so many other things' positions along with it. Deos the 300M have struts or a upper and lower control arms. I know some Chryslers have upper control arms, I'm not sure which ones.
You sure got me thinking on those two sided heads... I'm sure that by the time I get a car on the alignment rack that I'm able to turn the bolt by hand with a wrench if I choose. Do the splines bite into the knuckle or just the strut? I wonder if maybe the replacement struts we get have larger holes? While they do make sockets for those bolts, I don't have them. I tend to look only at what I'm working on, it's possible I may be thinking of Toyota cars which I know for a fact have hex-head bolts, and the front suspension is surprisingly similar. Are you sure that all GMs with that design have two sided bolts? I sure think I've done that on them, but you've got me to thinking I do that on something else... I just go,go,go... at the end of a busy day I couldn't tell you what the make of that day's first car was. My mind's razor sharp on some things, but on other things... CRS A co-worker got me pretty good by walking up to me holding a pushrod while I was just finsihing up a 3.1l lower intake. I was sure I would have put them all back in, but I sure don't remember it :rofl:, he told me he was joking around before I took anything back off... but he sure had me on that! The next time I have the struts off one I'll try to remember to pay attention and I'll post back with what I do.
That's understandable, I forget things all the time. All the GM strut bolts I've seen had the two-sided bolt heads but I can't say they all do. Maybe Chryslers have hex heads. On the GM strut there's like an inner metal part with "teeth" that grab the knuckle. I think the splines grab on the inner layer of the strut and the knuckle as well.
My impact is rated that torque @ 90 PSI, our shop air compressor kicks on at 150 PSI and the regulator's set to 175 PSI, so I'm sure that adds at least 50% to the output :)
Yeah you got the full sized 2-stage compressor :icon16:. But did you mean the compressor tank is set to 175 psi or the regulator to your impact 175 psi too and not 90 psi? I only run 90 psi because I'd think higher would damage my impact.
J-Ri
05-15-2009, 05:34 PM
It wasn't a strong pull, it was something that I personally would have probably ignored, but it was sure noticable. Letting go of the steering wheel on the highway it followed the exit ramp by itself :) If I remember right, negative camber and positive caster make it pull toward the side they're on, and I think that 1 degree of caster is equal in pulling force to .5 degrees camber.
I'm pretty sure it's a 3 stage actually (second head is kindda ovalish), it's very old, but it still works great. I'm not sure where the motor turns off or the maximum tank pressure, but the regulator on the outlet on the compressor is set to 175. The compressor turns on when the pressure drops to 150 PSI, so it's run at 150-175 PSI all the time. I thought it would damage it too, but when I started there everyone else was running theirs on it, and it's been fine for 5 years now. I personally think the extra torque is worth buying a new one even if it failed every 5 years. I have a little 33 gallon single stage compressor at home that only goes up to 125 PSI, and it feels so weak on that :)
I'm pretty sure it's a 3 stage actually (second head is kindda ovalish), it's very old, but it still works great. I'm not sure where the motor turns off or the maximum tank pressure, but the regulator on the outlet on the compressor is set to 175. The compressor turns on when the pressure drops to 150 PSI, so it's run at 150-175 PSI all the time. I thought it would damage it too, but when I started there everyone else was running theirs on it, and it's been fine for 5 years now. I personally think the extra torque is worth buying a new one even if it failed every 5 years. I have a little 33 gallon single stage compressor at home that only goes up to 125 PSI, and it feels so weak on that :)
manicmechanix
05-23-2009, 03:46 PM
Now I remembered what I disliked the most about the Camber being adjustable at the strut bolt, changinging Camber withing the steering axis changes the SAI and the scrub radius. It's bad enough changing changing one thing but three things at onc isn't good. Even if you wanted different Camber on each side you'd probably want the SAI and scrub radius to be the same on each side. Well I guess if the Camber is close on both sides then the SAI and scrub radius would be close too.
J-Ri
05-24-2009, 12:24 AM
SAI probably wouldn't change because the strut mount bolts would be in the same location, and the lower control arm can't be changed. Having the slotted holes in the strut tower wold be worse for maintaining SAI because adjusting the camber would directly change the SAI. I had to align my car two weeks ago after a little "unintended offroad adventure". Camber was off by about +1.5 degrees and the SAI was off quite a bit, but I don't remember exactly how much. I ended up using camber adjusting bolts (keeping whatever components I bent), and as I got the camber closer, the SAI kept getting closer and closer. I adjusted the camber to -1.5 degrees (about double the max. spec.) in the hope that "next time" I have slightly better cornering and stay on the road :). The SAI was still on, and while I had to look up "scrub radius", I assume it was very close because the car only pulls very slightly now. It will stay in the lane for 20-30 seconds before I have to correct it.
manicmechanix
05-24-2009, 02:11 AM
SAI probably wouldn't change because the strut mount bolts would be in the same location, and the lower control arm can't be changed. Having the slotted holes in the strut tower would be worse for maintaining SAI because adjusting the camber would directly change the SAI.
The way I understand it is the SAI is in relation to the axle centerline, so if you adjust the camber with the strut bolts you would also change the SAI, but if you adjust the position at the strut tower you would keep SAI the same while changing camber.
Edit: Actually I have this mixed up. Strut bolts keep the SAI the same like you were saying since SAI is measured between true vertical and the upper and lower strut pivots, which doesn't change. The camber changes and the scrub radius changes. With the adjustment at the stut tower SAI changes the same as camber, but I'm thinking scrub radius doesn't change. This is similar to how most SLA camber adjustment works too. I guess it's a matter of picking your poison, and camber changes always effect other suspension geometry.
I had to align my car two weeks ago after a little "unintended offroad adventure". Camber was off by about +1.5 degrees and the SAI was off quite a bit, but I don't remember exactly how much. I ended up using camber adjusting bolts (keeping whatever components I bent), and as I got the camber closer, the SAI kept getting closer and closer. I adjusted the camber to -1.5 degrees (about double the max. spec.) in the hope that "next time" I have slightly better cornering and stay on the road :). The SAI was still on, and while I had to look up "scrub radius", I assume it was very close because the car only pulls very slightly now. It will stay in the lane for 20-30 seconds before I have to correct it.
I forget the rule..if your camber is off but your SAI is OK it's a bent strut, and if your camber is ok but your SAI is off..I'd have to look that up . Well if adjusting Camber with the strut bolts changed SAI when you readjusted Camber then it looks like it's true that changing camber by the strut bolts does change SAI and scrub radius too. Anyway, I'm going to guess your car's strut got bent. Does it show any sign of binding when you press down on it?
The way I understand it is the SAI is in relation to the axle centerline, so if you adjust the camber with the strut bolts you would also change the SAI, but if you adjust the position at the strut tower you would keep SAI the same while changing camber.
Edit: Actually I have this mixed up. Strut bolts keep the SAI the same like you were saying since SAI is measured between true vertical and the upper and lower strut pivots, which doesn't change. The camber changes and the scrub radius changes. With the adjustment at the stut tower SAI changes the same as camber, but I'm thinking scrub radius doesn't change. This is similar to how most SLA camber adjustment works too. I guess it's a matter of picking your poison, and camber changes always effect other suspension geometry.
I had to align my car two weeks ago after a little "unintended offroad adventure". Camber was off by about +1.5 degrees and the SAI was off quite a bit, but I don't remember exactly how much. I ended up using camber adjusting bolts (keeping whatever components I bent), and as I got the camber closer, the SAI kept getting closer and closer. I adjusted the camber to -1.5 degrees (about double the max. spec.) in the hope that "next time" I have slightly better cornering and stay on the road :). The SAI was still on, and while I had to look up "scrub radius", I assume it was very close because the car only pulls very slightly now. It will stay in the lane for 20-30 seconds before I have to correct it.
I forget the rule..if your camber is off but your SAI is OK it's a bent strut, and if your camber is ok but your SAI is off..I'd have to look that up . Well if adjusting Camber with the strut bolts changed SAI when you readjusted Camber then it looks like it's true that changing camber by the strut bolts does change SAI and scrub radius too. Anyway, I'm going to guess your car's strut got bent. Does it show any sign of binding when you press down on it?
J-Ri
05-24-2009, 02:53 AM
SAI is basically the angle of the strut compared to vertical. http://www.familycar.com/alignment.htm. By moving the strut you change that, but by moving the steering knuckle you keep it closer.
I worded that last post wrong... what I meant is that since the strut mount bolts don't move, if you adjust camber to where it should be, the SAI should be good too. That assumes that nothing in the steering/suspension is bent. If part of the body/subframe was bent, I'd imagine you'd need to elongate the strut tower holes to adjust SAI and camber seperately. I'm guessing it's the strut that's bent too, but it doesn't bind at all. I had a little understeer going around a highway offramp way too fast... I would have been fine if not for some sand around the outside 4' of the pavement... hit that and the next thing I knew I was in the median/ditch. The wheels hit sideways hard enough that grass got packed into the beads, so I'm sure it bent something.
I worded that last post wrong... what I meant is that since the strut mount bolts don't move, if you adjust camber to where it should be, the SAI should be good too. That assumes that nothing in the steering/suspension is bent. If part of the body/subframe was bent, I'd imagine you'd need to elongate the strut tower holes to adjust SAI and camber seperately. I'm guessing it's the strut that's bent too, but it doesn't bind at all. I had a little understeer going around a highway offramp way too fast... I would have been fine if not for some sand around the outside 4' of the pavement... hit that and the next thing I knew I was in the median/ditch. The wheels hit sideways hard enough that grass got packed into the beads, so I'm sure it bent something.
manicmechanix
05-26-2009, 02:58 AM
SAI is basically the angle of the strut compared to vertical. http://www.familycar.com/alignment.htm. By moving the strut you change that, but by moving the steering knuckle you keep it closer.
I worded that last post wrong... what I meant is that since the strut mount bolts don't move, if you adjust camber to where it should be, the SAI should be good too. That assumes that nothing in the steering/suspension is bent. If part of the body/subframe was bent, I'd imagine you'd need to elongate the strut tower holes to adjust SAI and camber seperately.
Yeah I mixed my last post up too and added an edit. I guess that's what happens when posting late at night and after a few beers :). Yeah SAI is the angle of the strut steering points to the vertical. So adjustble strut bolts at the knuckle don't change SAI while changing camber, but scrub radius changes. Adjusting the strut mount changes SAI while chamging camber but ot scrub radius. Bottom line I think is to adjust both sides camber equally which ever the setup so that scrub rdius or SAI is also equal, assuming nothing is bent or worn.
I'm guessing it's the strut that's bent too, but it doesn't bind at all. I had a little understeer going around a highway offramp way too fast... I would have been fine if not for some sand around the outside 4' of the pavement... hit that and the next thing I knew I was in the median/ditch. The wheels hit sideways hard enough that grass got packed into the beads, so I'm sure it bent something.
Yeah the strut is usually the weakiest link and takes the brunt of an impact, so its usually is the first to bend. I remember you said the SAI was off in addition to camber. That would indicate that one or both of the steering pivot points moved (lower ball joint or/and upper strut mount). Or the setback has shifted. Basically something that would move the locations of the steering pivot points. SAI is a diagnostic angle as is setback. Is the caster off too? That would indicate the setback is off. Sometime the crossmember can be loosened and shifted back into alignment.
I worded that last post wrong... what I meant is that since the strut mount bolts don't move, if you adjust camber to where it should be, the SAI should be good too. That assumes that nothing in the steering/suspension is bent. If part of the body/subframe was bent, I'd imagine you'd need to elongate the strut tower holes to adjust SAI and camber seperately.
Yeah I mixed my last post up too and added an edit. I guess that's what happens when posting late at night and after a few beers :). Yeah SAI is the angle of the strut steering points to the vertical. So adjustble strut bolts at the knuckle don't change SAI while changing camber, but scrub radius changes. Adjusting the strut mount changes SAI while chamging camber but ot scrub radius. Bottom line I think is to adjust both sides camber equally which ever the setup so that scrub rdius or SAI is also equal, assuming nothing is bent or worn.
I'm guessing it's the strut that's bent too, but it doesn't bind at all. I had a little understeer going around a highway offramp way too fast... I would have been fine if not for some sand around the outside 4' of the pavement... hit that and the next thing I knew I was in the median/ditch. The wheels hit sideways hard enough that grass got packed into the beads, so I'm sure it bent something.
Yeah the strut is usually the weakiest link and takes the brunt of an impact, so its usually is the first to bend. I remember you said the SAI was off in addition to camber. That would indicate that one or both of the steering pivot points moved (lower ball joint or/and upper strut mount). Or the setback has shifted. Basically something that would move the locations of the steering pivot points. SAI is a diagnostic angle as is setback. Is the caster off too? That would indicate the setback is off. Sometime the crossmember can be loosened and shifted back into alignment.
kokamojoe
06-18-2011, 01:59 AM
I know the posting is old but letting the bolts grind the spindle out isn't cool. That's permanent damage to the spindle. The fastest and easiest way I have found is to get the vehicle compt in then on any brand of vehicle that has 2 bolts holding the strut to the spindle take the upper bolt out & grind it off & the loosen the bottom bolt & let the wheel fall outward tighten the upper bolt then the bottom. the camber will be as good as it gets with out selling a cam bolt kit. The tools needed are, a good impact swivel I prefer a Wright brand swivel, http://www.wrighttool.com/online_catalog.asp, a set of good deep well impact sockets, and a good air hammer to knock out the upper bolt & to knock the bottom one loose after you reinstall the upper bolt. And if you sell some cam bolts keep the old bolts grind them to have them ready for the next car. As far as a helper goes you shouldn't need one very often.
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