Transmission problems - PeachParts Mercedes-Benz Forum

dannym · #1 06-09-2008, 07:57 AM

Greeting everyone!

Here's the story-
About a week ago I was driving to the airport and the transmission just dropped out. I thought I caught it during a downshift and didn't think too much of it.
Then yesterday I took my jetski out to the lake about a 20 mile drive, all highway. Got there with no problem at all, had a lot of fun.
Going home is when it really started acting up. I get on the highway and about a mile down the road the transmission drops down a gear. Engine revving I could only get about 50 mph or so. So I get off and stop. Run it through the gears. All seems fine so I get back on the highway.
It worked fine for a while but about 2 miles from my exit it does it again. This time it totally drops out. Engine revving, going nowhere.

I put it in neutral and back in drive and it works. I barely limped home.
I thought maybe it had something to do with the trailer but this morning it did the same thing. I got to work fine but the street outside is a 25mph zone. I was doing 25 - 30 and the transmission drops out again. Engine revving, no power. So now I'm worried.

I checked the transmission fluid and it's fine. Level is good and it's nice and red like new.
It has low miles, around 180,000. Do these transmissions need to be serviced at this low mileage?

Any ideas what could be wrong and how to fix it? This is my daily driver I really need it working.

Thanks

Danny

DeliveryValve · #2 06-09-2008, 11:10 AM

Sounds to me the B2 piston is binding. I would look into that first.

rkohut · #3 06-09-2008, 12:36 PM

Quote:

Originally Posted by DeliveryValve

Sounds to me the B2 piston is binding. I would look into that first.

Sounds like it. Does reverse work all the time?

dannym · #4 06-09-2008, 01:10 PM

I have never noticed any problems with reverse. Don't really use it very much. I backed the jetski into the water with no problems.

I'm gonna do a search on the B2 piston.

rkohut · #5 06-09-2008, 01:20 PM

Quote:

Originally Posted by dannym

I have never noticed any problems with reverse. Don't really use it very much. I backed the jetski into the water with no problems.

I'm gonna do a search on the B2 piston.

You'll find that when reverse works fine and forward gears are having problems, it's classic B2

dannym · #6 06-09-2008, 01:40 PM

Ok thanks for the info.

I see two parts listed one plastic and one metal. Which one do I want?

rkohut · #7 06-09-2008, 01:43 PM

Check this out

http://www.dieselgiant.com/Mercedesb2pistonsealreplacementl.htm

dannym · #8 06-09-2008, 01:43 PM

Nevermind. The plastic one is the B-1 piston.

dannym · #9 07-07-2008, 08:26 AM

SO I finally got around to replacing the B2 piston yesterday. Just in time too cause the slipping was getting worse.

I was supprised how easy it was. I did drop the transmission a little but I did not remove any of the exhaust. In the end it wasn't necessary at all I think.
The hardest aprt was getting the o-ring in place. The whole job took roughly 1 1/2 hours from start to finish.

I didn't see anything broken but it's shifting great now.

Danny