Problems in reverse

08-16-2001, 09:42 PM
I've been hanging out here for a while & I must say I've learned a lot. This is the first time I've had to post something but it's a big one.

I have a '91 G20 automatic. When the car's cold everything's fine. After the car warms up, if I park or for any reason need to go in reverse, I can't. I put the car in reverse and noting happens. If I rev the engine a bit, sometimes it will slam into gear but I know this can't be good for the transmission.

The fluid is fine (not low or excessively dirty). Like I said this only happens after the car has warmed up. This leads me to think that it has something to do with the fluid not flowing correctly after the transmission warms up. Then again, I could be totally way off base 'cause I know jack about trannys.

Please help....


T4 Primera
08-17-2001, 03:25 AM
Next time it does it, instead of revving the motor, try moving the shifter back and forth just a little with the detent button in. If it goes into reverse while doing this you may just need to adjust your selector cable.;)

08-17-2001, 07:03 AM
Thanks for the tip but I've tried that. Still no go.

Keep 'em coming...

T4 Primera
08-18-2001, 11:16 PM
Since you have no problems when the trans is cold, and it sometimes engages when you rev the engine a little, then fluid pressure is what is making a difference.

Did a little search and found something that is quite likely to be causing your problem, the fluid filter in the pan may be clogged up which would give the above pressure problems. Check out the second and third paragraph of this link.

Please post your findings if you solve the problem for the benefit of others.;)

08-23-2001, 02:24 PM
Thanks a ton for the link. I changed the fluid & filter and I must say, it helped a lot. Now it shifts into reverse even when hot.

However, sometimes it does not shift into reverse when hot. But even when it does not engage, it only takes a tap on the gas to get it in there. Not like the rev I used to have to give it.

This leads me to belive that the fluid may be getting clogged somewhere else like it obviously was in the filter. Per the article T4 Primera pointed me to, I'm going to clean out all of the transmission fluid lines and the cooler in the bottom of the radiator.

Any tips on doing this?


T4 Primera
08-23-2001, 10:17 PM
Looks like we're on the right track now. All I can suggest for the cooler circuit is to try to do a reverse flush similar to reverse flushing a radiator. This would mean disconnecting both pipes to/from the cooler and finding a way to flow fluid through it in the reverse direction.

I've spoken to our local (and very good) specialist Keith Marshall who confirmed it is an oil pressure problem and his opinion is that the above will not improve things much. However, he did suggest that to prove it one way or the other, you could bypass the cooler for a day (loop a temporary pipe between the inlet and outlet to the transmission or around the cooler) and see if it makes a difference.

A reputable transmission specialist will likely have a rig for reverse flowing the cooling circuit on the car and so shouldn't break the bank to get done if the bypass thing makes a difference. Keith said that when coolers get clogged like this they tend to replace them with a new cooler. Luckily, aftermarket coolers are generally not hard to fit and not too expensive.:)

Failing the above, I'm afraid he said that it becomes a "transmission out" repair, so it's worthwhile exploring the above alternatives first.:( Keith's one of the best transmission people around although it's always possible he could be wrong - lets hope so. I believe Clark Steppler (the source of info for the previous link to is a Nissan tech guru without peer so his opinions on this do carry a lot of weight.

If need be I could scan the transmission removal/refitting pages of my Haynes manual and email it to you. You would need to let me know the transmission type you have (listed on the build plate) though it should be a RLF03A.

Good luck and keep posting your findings ;)

08-24-2001, 06:50 PM
Excellent. I knew I could solve this without resorting to a tranny shop (with everyone's help here of course).

I thought about just taking the radiator out and flushing water through it with a high pressure sprayer at the local car wash. Then making SURE that it's completely dry before putting it back on the car.

Any opposition to this?

What about getting a new radiator? has them for $145 with free overnight shipping.

Also, You mentioned that you have a Haynes manual for this car! WHERE DID YOU GET IT!!!??? I've been looking for an aftermarket repair manual since I bought the car. I have the factory service manual but it is a little difficult to work with at times, as my recent double driveshaft replacement (step-by-step in the works to be posted soon) proved. The FSM was absolutely no help whatsoever. If you (or anyone else for that matter) has a line on a Haynes manual (Chilton sux), please share...

Thank to all....

T4 Primera
08-24-2001, 08:22 PM
Are you gonna bypass the cooler first to check if it will make a difference before you go to all that other trouble?
Careful not to overpressurize that cooler when you clean it. Don't know about using water though.
Rather than get a replacement radiator it might be cheaper to get an aftermarket tranny cooler and fit that. You could then just leave the old cooler where it is. My mitsi's a manual but I fitted an auto radiator and the cooler just sits there empty. Don't even need to plug up the pipes once it's drained.

The manual?? I got mine from the local Repco supplier for $65NZ. Remember this was written for UK/Euro Primeras.
It doesn't contain any info about the internals of the auto tranny, just removal/refitting, cable adjustments etc.
Book 1851 - get it here
or maybe there is a supplier nearer you.

Keep posting, there seems to be a couple more out there with similar problems.

08-24-2001, 09:38 PM
You're right. I should try the bypass thing first.
I'll do that tomorrow & post later on the results.

Thanks for the link to the book. Haynes (US) does not make a book for the G20 (or any other Infiniti). Do you know if there's any major differences between the Primera and the G20?

If not, I'll probably get the Primera book.


T4 Primera
08-25-2001, 01:37 AM
Do you know if there's any major differences between the Primera and the G20?

No, I don't know if there are any major differences. I'm sure they have more in common than they have differences though. I just took a punt on the book because my Primera is AWD and JDM only so that part of it ain't covered. My only other option was the FSM that the local dealerships use - cost $700NZ. Maybe the parts guy of an Infiniti dealership can hook you up with a better alternative.

Just remember that while you have the cooler bypassed there ain't no cooling. So test it and stop driving it until the cooler is hooked up again. Nothing kills autos faster than overheating (apart from no fluid that is).

Good to see your keeping the info flowing, wish more people would do that:D :D

08-25-2001, 07:39 AM
I have the factory service manual that came with my car and id is OK. I think it is written with the assumption that you are an experienced mechanic and it leaves out a lot of the little details. Also, there's a lot of stuff that I can't do because I don't have a Infiniti diagnostic machine.

I look at the FSM every time I start something but more often than not, I end up figuring it out as I go. That's why it took me 6 hours to change 2 axles recently.

I also have a Chilton's manual but it's no better than the FSM. I has even less detail because it covers Nissan & Infiniti cars & Nissan Trucks all in the same small book. Basically it's just a badly made copy of the FSM with all of the technical stuff left out.

Calling all G20 owners!
Lobby Haynes for a US G20 manual!!
Information is power and what are we trying to do with or G20s? That's right, more power. We need that manual! Or, at least I do.


04-16-2002, 12:29 AM
Hello there,
not sure if anyone is watching this thread anymore, but i'll post anyway.

our family recently purchased a 1999 g20t. and it is an automatic.
it has a few problems.

in the morning, or if it has gotten cold and sat for awhile, when you go into reverse, there
is a lot of vibration and metal rattling, it only occurs in reverse gear, once in anything other
than reverse, the odd behaviour ends. also, when the vehicle is nice and warm, it too shows no odd behaviour.
it does seem to also shift a little harsh while in the lower rpm ranges, 2000 rpm...

can anyone tell my what is wrong with it? is this normal? and would it be covered under infiniti's powertrain warranty?

thanks all

01-12-2004, 01:05 AM
Thanks for the info. I recently purchased a 1990 Nissan Primera which has the same problem in the first post (not going into reverse when hot).

I will take this information to a transmission guy and hopefully it will fix my problem too.

Add your comment to this topic!