1999 Saturn SL2 Lost Reverse

[1999DOHCSL2]

I just recently realized the whole reverse slam problem, and my brothers saturn SL2 was doing that not long ago. Recently while driving it I noticed it would bump twice when shifting into reverse. Now it has no reverse at all, it rolls a tiny bit if I rev it high enough but that's about it. Its an automatic, also it bumps when going into second depending on how I ride the gas pedal. Whats up with his car? Could it be a shaft nut problem?

[1994Saturn]

valve body.... these transmissions need the fluid changes every 30k miles max..

[OnDaGround]

Originally Posted by 1994Saturn

valve body...

+1 so when you noticed the reverse slam you did not do the cure from wolfman in the How-To library?

[1995sl1sohc]

The valve body needs to be replaced, and if it is bumping into 2nd you are probably looking at a loosened input shaft nut as well. Replace both of them and torque the input shaft nut to 111 ft/lbs, and check the output shaft nut as well and make sure it is torqued to 111 ft/lbs or just replace it as well and you should be fine, just make sure you keep up with regular fluid and filter changes or it might happen again. It is a pretty easy DIY job, it's just time consuming taking out all the bolts.

[1999DOHCSL2]

Thanks alot for the quick replies, this chick is going to be selling her 97 4 door i think its an sl2 aswell. She is starting to have the reverse slam problem. I want my brother to buy her car and use swap trannies, is this possible?

[braddojm]

Just replacing the input shaft nut fixed that problem on my '97 SL2.
I would start there - only a $35 fix (nut, gasket, filter).

[1999DOHCSL2]

It fixed reverse not working? I have a good feeling that could be the problem. I didnt try the reverse slam fix because I just learned about it last night when I was looking for why the reverse stopped working. Also my brother never changed the transaxle pil or filter.

[braddojm]

Yes, it fixed the reverse not working. Mine started as a delay engaging reverse and then quickly to no reverse and very sloppy first to second shifts. Replaced the nut and all is well (been about 3 months now).

[1995sl1sohc]

I believe the 1997 and 1999 MP7 transmissions have different gear ratios making them incompatible.

[Special Forces]

Originally Posted by 1995sl1sohc

The valve body needs to be replaced, and if it is bumping into 2nd you are probably looking at a loosened input shaft nut as well. Replace both of them and torque the input shaft nut to 111 ft/lbs, and check the output shaft nut as well and make sure it is torqued to 111 ft/lbs or just replace it as well and you should be fine, just make sure you keep up with regular fluid and filter changes or it might happen again. It is a pretty easy DIY job, it's just time consuming taking out all the bolts.

^^^ Everything that needed to be said in a nut shell.

Originally Posted by braddojm

Just replacing the input shaft nut fixed that problem on my '97 SL2.
I would start there - only a $35 fix (nut, gasket, filter).

Sorry, you just fixed the symptom not the source. Expect it to come back in the near future.

The valve body is the source of the reverse slam. The slam is continually taking it's toll on the input shaft nut. Eventually it loosens and now you don't have any reverse and a problem in forward gears.

Replacing the valve body fixes the slam and torquing the input shaft nut fixes the no reverse and forward gear problems. Just doing one is not fixing the problem only patching it.

[1999DOHCSL2]

How easy is it to change the valve body? He thinks its my fault the car wont go backwards anymore because I always took it street racing every saturday since I started driving it. Don't worry I only raced it once, all other times I was just spectating. Anyway, I would like to fix it for him if possible, the other day I was bored and took the driver side wheel off. I took the plastic cover off and saw the side of the transaxle, look like it had 12 bolts. I wondered if that's where the shaft nut was but I didn't have the balls to open it. Also, everytime I shift into reverse, I hear like a rattling noise inside the engine(or tranny), maybe a loose part??

[Special Forces]

Originally Posted by 1999DOHCSL2

How easy is it to change the valve body? He thinks its my fault the car wont go backwards anymore because I always took it street racing every saturday since I started driving it. Don't worry I only raced it once, all other times I was just spectating. Anyway, I would like to fix it for him if possible, the other day I was bored and took the driver side wheel off. I took the plastic cover off and saw the side of the transaxle, look like it had 12 bolts. I wondered if that's where the shaft nut was but I didn't have the balls to open it. Also, everytime I shift into reverse, I hear like a rattling noise inside the engine(or tranny), maybe a loose part??

It takes about an hour for someone who has minimal mechanic inclination. It's on top of the transmission and can be found underneath the battery and battery tray (you'll see the harness going to the top of the transmission).

The one time racing didn't do it. It's a matter of keeping up on fluid changes to keep the transmission and valve body clean. It also helps when it's caught in the earlier stages and even caught before the input shaft nut comes loose.

The side piece you saw on the transmission is where the input shaft nut is. Good thing you didn't open it casually as you would have dump most of the ATF out of the transmission on the ground. The rattling noise is probably the nut if you really really backed it off which is possible from the sounds of no reverse what so ever.

So you're fix as I mentioned above is two parts. New valve body and tightening the input shaft nut.

[1999DOHCSL2]

Dude, I am 18 years old. I have no mechanical inclination whatsoever, but I love cars, and I love Saturn. I cant believe you just basically repeated to the teeth what I thought this whole time was happening to my brothers car while I was driving it. I want to be a mechanic, everyone tells me I cant be. Anyway, I drained the fluid before I was going to pop off the shaft nut housing thing, but I just didn't have the courage to do it. I am glad you said my racing didn't do it, I am going to make my brother read this in the morning. I beat a mid 90's 5-speed manual accord with a stock 99 SL2 Auto lol. Saturn's sure can take some hell man. Whats the easiest way to learn how to replace a valve body?

[1995sl1sohc]

Go to the how to library and search for reverse slam fix or valve body or something. I believe there are a couple of how to's kicking around with pictures etc. that are very helpful.
Just doing the nut replacement is as special forces said a short term fix. Eventually the nut will work it's way loose again and you'll lose your gears again. Do it right the first time.
The cause of this was the transmission being neglected and not properly maintained. Just in case your brother wants to hear it from more then 1 person .

[Laura Rife]

Where can you purchase an inout shaft nut in So Cal?