Loosing reverse or something less serious? - PeachParts Mercedes-Benz Forum

lsmalley · #1 03-19-2011, 12:19 PM

I have been loosing reverse on my car, but why is it that in the morning on a cold start the reverse is fine, but after the car is warm it doesn't work? Am I really loosing reverse or is there something else going on?

JohnM. · #2 03-19-2011, 06:11 PM

I hate to be the bearer of bad news.......

lsmalley · #3 03-19-2011, 06:23 PM

Dammit! Does that mean I'll lose all the other gears too?

JohnM. · #4 03-19-2011, 06:57 PM

No. Typically you only lose the reverse gear, not forward too. If you are lucky, doing a filter and fluid swap will sometimes be enough to cure the problem...if it has been awhile since doing so.

lsmalley · #5 03-19-2011, 07:05 PM

I am the unlucky one then. I did a filter and fluid change along with new pan and gasket within the past 5-6 months....unfortunately I did not know (and still don't know) where the torque converter is or how to drain it, so I just flushed my transmission 4 or 5 times hoping that whatever was in the torque converter was replaced with the new fluid.

JohnM. · #6 03-19-2011, 08:14 PM

Doing the torque converter is a good idea because the old fluid in there is just going to contaminate the fresh stuff, was there any particles or crud in the old transmission fluid?

lsmalley · #7 03-19-2011, 08:39 PM

nope, no particles whatsoever

ps2cho · #8 03-19-2011, 08:46 PM

fluid is thicker in the mornings so it grabs easier, once warm and more viscous it fails.

....but didn't we already go through this in your last thread?

lsmalley · #9 03-19-2011, 08:51 PM

yeah, something about B3 clutch someone mentioned, but sometimes orr works

deanyel · #10 03-19-2011, 11:26 PM

Sounds to me like a blown reverse piston seal. When cold it fills up a little faster than it leaks out, which then reverses when the fluid gets warm. But it doesn't really matter, seals or clutches - the transmission has got to come out either way.

lsmalley · #11 03-20-2011, 12:43 AM

I watched a video of someone replace a piston of some sort....it looked pretty simple. maybe it was a K1 piston? anyways, could it be a quick fix until I get it rebuilt?

deanyel · #12 03-20-2011, 12:07 PM

K1 shift kit has to do with shift quality for forward operation. You may be thinking of B2 piston repair, which can be on car, but that too is forward operation. I've not ever heard of a on the car fix for the reverse problem. You could try one of those slipping clutches transmission additives - can't see that you've got much to lose.

lsmalley · #13 03-20-2011, 12:24 PM

Well I think it was a youtube video.....the part looked like the inside of a pen (my closest analogy if it) where there was a spring, a plastic piece, and maybe something else where he removed a small 4 screw (flat head) plate and took out the old spring and replaced it with the new one. But no worries, I'll start saving for the rebuild. I don't think I've tried an additive, can't remember, but I guess its worth a shot until I can get the rebuild. How much does a typical rebuild cost.....assume that most gears and seals will be done?

sptt · #14 03-20-2011, 08:06 PM

That is the K1 Spring kit. Just helps with shifts, not reverse issues. The Piston is a whole different animal.

Jim_P · #15 03-21-2011, 11:10 PM

I had the same problem with my 90' 300e. It's a common failure on these transissions. I ended up having the unit rebuilt. It only had 200K mikes on it, don't know why it failed.

-Jim