Losing Reverse, 1991 300CE, 722.359 tranny - PeachParts Mercedes-Benz Forum

glenmore · #1 01-19-2011, 10:59 PM

1991 300CE with 172m. I've owned the car since 111m and this is the first instance of tranny problems. I noticed that when shifting into reverse there in no "tug" as it engages as there usually is. After shifting into reverse and noticing this I would be very ginger in applying gas. Anything other than a very light touch and there is a noticeable bump as it engages. The car will travel in reverse after the bump as normal, then forward gears are normal.

Bad news? Adjust fluid level? (Pray) Modulator valve?

lsmalley · #2 01-19-2011, 11:16 PM

does the car take a while to go in reverse? if you add gas does it respond immediately or does it rev up and slowly start to go in reverse? I'm currently having the same problem, it would be interesting to see what it is. Try checking the fluid level, the vacuum line, and the modulator.

glenmore · #3 01-20-2011, 12:15 AM

Quote:

Originally Posted by lsmalley

does the car take a while to go in reverse? if you add gas does it respond immediately or does it rev up and slowly start to go in reverse? I'm currently having the same problem, it would be interesting to see what it is. Try checking the fluid level, the vacuum line, and the modulator.

It revs a bit and slowly goes into reverse. I am almost certain that if I give it too much gas too quickly and it will engage with a "bang".

compu_85 · #4 01-19-2011, 11:28 PM

The 722.3 in my SDL did a similar trick... it started taking longer and longer to engage, then wouldn't engage till you reved it, then it quit all together

-J

lsmalley · #5 01-20-2011, 03:17 AM

I'm guessing the transmission is going out. anyone else wanna chime in on this? try looking at some posts by mb d.o.c, he has great knowledge on this.

Ferdman · #6 01-20-2011, 04:20 AM

glenmore, transmission fluid & filter should be changed every 30,000 miles. If you don't follow that routine change the fluid & filter and see if that helps/resolves the condition.

Ivanerrol · #7 01-20-2011, 05:10 AM

Pull the transmission pan and look for signs of sediment in the bottom of the pan. If there is then changing the filter and tranny oil is fruitless.
Clutchpack or rebuild for you.

Ferdman · #8 01-20-2011, 08:08 AM

Dropping the transmission pan without first draining the fluid is a mess waiting to happen. Good luck with that approach.

mbboy · #9 01-20-2011, 08:10 AM

I've been having the same trouble with my 722.34. Check out the thread "Transmission Quandry" for more info on the problem.