vibration from driveshaft on 96 sonoma 2WD

[priller13]

I own a 1996 S-15 Sonoma 2.2 4cyl, standard 5 speed trans, short bed, standard cab. I have owned it since it was new, so I know the history of the truck. I have relegated the truck to "second car" status now due to its age, but it only has 76K miles on it. A few weeks ago, the U-joints began squeaking so bad I had to replace them. Why Detroit insists on putting U joints on that don't have grease fittings is beyond me. I was unable to remove the existing U joints using a vice and a couple sockets like normal as a press the way that the Haynes service manual described, so I took it to Pep Boys and they removed them for me. They had to heat them to get the plastic retainers to break. I installed new U joints, making sure to realign the driveshaft at both ends, but now the truck has a terrible vibration from around 35 mph up. Does anyone have any ideas as to what went wrong? Could Pep Boys have bent or warped something while heating up the old U joints to remove them? Does the driveshaft need to be rebalanced? The new U joints do have grease fittings in them so they are not going to be the exact same weight and balance as the original U joints. Any idea (without having to spend hundreds of dollars for trial and error) would be appreciated.

[GMMerlin]

Originally Posted by priller13

I own a 1996 S-15 Sonoma 2.2 4cyl, standard 5 speed trans, short bed, standard cab. I have owned it since it was new, so I know the history of the truck. I have relegated the truck to "second car" status now due to its age, but it only has 76K miles on it. A few weeks ago, the U-joints began squeaking so bad I had to replace them. Why Detroit insists on putting U joints on that don't have grease fittings is beyond me. I was unable to remove the existing U joints using a vice and a couple sockets like normal as a press the way that the Haynes service manual described, so I took it to Pep Boys and they removed them for me. They had to heat them to get the plastic retainers to break. I installed new U joints, making sure to realign the driveshaft at both ends, but now the truck has a terrible vibration from around 35 mph up. Does anyone have any ideas as to what went wrong? Could Pep Boys have bent or warped something while heating up the old U joints to remove them? Does the driveshaft need to be rebalanced? The new U joints do have grease fittings in them so they are not going to be the exact same weight and balance as the original U joints. Any idea (without having to spend hundreds of dollars for trial and error) would be appreciated.

Is this a 1 piece or 2 piece driveshaft?
Did you mark the relation of the driveshaft to the pinion flange?
Was the 2 pieces of the driveshaft reinstalled in the same location (in relation to each other)?
The Haynes manual is incorrect on its u-joint removal and installation procedure also the use of heat can weaken the metal causing it to distort or lose temper causing a failure of the driveshaft.
There are SPECIFIC tools and procedures to remove u-joints without causing damage.
So either you or Pep boys damaged the shaft, the u-joints are incorrectly installed causing them to bind or the shaft was incorrectly installed
Saved a bunch of money doing it yourself didn't you

[priller13]

Thanks for the reassurance GMmerlin........ you are a GM mechanic sounds like. I really don't appreciate the self righteous attitude and it is know-it-alls like you that give user forums bad names. You leap to all these conclusions when you don't know anything about me or my experience. I used to be a certified mechanic and body man and have removed and replaced countless U joints before. I admit I haven't kept busy with the trade, but I know my own vehichles and know how to take care of them. When I ran into something I didn't know how to handle, I paid a professional to remove the U joints at Pep Boys........... If Pep Boys didn't have the expertise or equipment they should have declined the work. Even though I chose to leave the automotive service profession about 18 years ago, I still service and maintain my own vehichles. I'm sorry, but the principles of servicing a car have changed, but they haven't changed that much. The pin head engineers who devise new fasteners and new methods are just pandering to management because they figured out a way to save a few cents per vehichle and they are also pandering to dealership mechanics who think they have all the answers. I can redo things a lot of times before I ever reach the $75-$95 an hour I would have to pay a "professional" to do it. The "professionals" that I worked with and managed were more concerned about getting off and going to get high again or have a few more beers......... the exceptional mechanic and bodyman were just that an exception. So keep your insults to yourself and stay off these forums if you don't have anything helpful to say.

[GMMerlin]

Save me the "I'm an ex-mechanic I know what I am doing bit"
If you knew what you were doing, you wouldn't be having the problem you are having.
I asked you some questions to try to find out what is going on and you want give me a bunch of shit.
Stop blaming everyone for your problem. You worked on it and you messed it up.
And yes the technology of vehicles has changed in the last 18 years. That includes something as simple as a u-joint.

You leap to all these conclusions when you don't know anything about me or my experience.

And you didn't jump to a conclusion about me? Thats the pot calling the kettle black.

The "professionals" that I worked with and managed were more concerned about getting off and going to get high again or have a few more beers.

If you want help, answer my questions..if not, take your toys and go home.

[priller13]

QUOTE: Save me the "I'm an ex-mechanic I know what I am doing bit"

GM Merlin,

First of all, it was not my intention to go to a car help forum and insult anyone or be insulted. I apologize for sterotyping mechanics. My personal experiences in a shop environment have created a general distrust for any automotive service tech that I don't know personally. You should not have taken the remarks personally if they don't apply. It is not possible for any one person, a working mechanic or the car owner, to know everything about every possible problem on that particular make and model. That's why forums work......... so people can exchange experiences and knowledge.

I don't feel that I am an "ex mechanic". I have the belief that I am a former professional mechanic who left the trade to pursue other interests that were better suited to my education. I don't work on anyone's cars but my own. There isn't a week that goes by that I don't work on something on one of my 2 cars, 2 trucks or my motorcycle. I have 2 cars that are under restoration and 2 that are dailey drivers. When I don't know something, I stop and ask or pay someone to help or advise, hence the trip to Pep Boys on the U joints. I was doing this on a weekend (Saturday & Sunday) so the choices for professional help were limited on those days.

Yesterday at lunch, I called a clutch & drive shaft garage in town and the owner there told me I didn't do anything wrong, I just haven't finished the job. He informed me that the GM drive shafts that have the U joints held in with nylon retaining rings often need rebalancing when aftermarket U joints are used to replace them. The added weight of inside snap rings and grease fittings are enough to cause the driveshaft to be out of balance. I have an appointment for him to rebalance the driveshaft on Saturday.

So with that said, again I apologize for insulting you, but I think an apology from you is in order. I didn't use any 4 letter words in my response and didn't blame anyone but myself for my problem. I asked if Pep Boys MIGHT have caused a problem by heating up the driveshaft to remove the old U joints. Every mechanic I have talked to after the fact tells me that is an appropriate way to deal with their extraction. I think if you want to be treated like a professional, you need to talk and act like one. Perhaps you would take a little constructive criticism and work on your bed side manner, Dr. GM Merlin on a forum such as this.......... the choice of where I spend my money on my truck will always be mine, and I don't need GM, their dealerships or disillusioned mechanics telling me I'm not qualified to repair my own truck. You simply don't know enough about me to make such sweeping remarks.

[GMMerlin]

You apologize and yet throw insults…go figure
The fact is that heating a driveshaft has never been an acceptable method to remove nylon injected u-joints nor is it an approved method by the company and compainies that designed, built or installed the prop shaft on your vehicle (that goes through all the Tier1 and 2 suppliers that supply the components) and every “mechanic” you have talked to is WRONG.
Like I told you in the first reply, heating the driveshaft can distort or weaken the metal and could lead to premature driveshaft failure.
Talk to a trained “Technician” and he/she will tell you the proper procedure as outlined in GM service information.
The fact is that most driveline vibrations after repairs are caused by incorrect repair procedures..Failure to mark the relationship of driveshaft to the pinion flange is the most common mistake that is made.
That is why I asked the questions and made the suggestions to check your work first before going in other directions…
Hopefully the clutch guy will have success in balancing the driveshaft to eliminate your concern..
Personally I would have test driven your vehicle with you and an Electronic Vibration Analyzer to determine if you vibration was caused by a balance or u-joint concern before I made any repairs, if he is wrong, what are you going to do next?
As a professional technician, I prefer to verify and properly diagnose the concern before I offer repair advice, even if I believe it is a common problem with a common repair.
Shot gunning repairs or the try this, try that method only leads to customer dissatisfaction.