Tonight when I was leaving work, I started the car after several tries, and let the car warm up for a few minutes. When I put the car into S, it wouldn't completely engage in first gear. I let off the pedal, and gently pressed it again, and it caught. If I pushed to far it seemed to partially disengage. Second, third, and fourth all seem fine. Reverse is great. Any thoughts? I am not sure, but I don't think we broke 20 today here, don't know if its a temperature related thing or not.

__________________
Chris

82 300SD

I would check your trans fluid level first. Check it with the engine idling in neutral and the engine somewhat warm and post back if this is not the problem, ok?

As already said, check fluid level, if ok, and it's been a while since you changed the fliud and filter, thats the next thing to try, if that doesn't fix it theres an internal problem. I've had a trans fail like that before in the past, suddenly just had no grab in one gear, it turned out the lip seal on the clutch pack servo had gotten hard with age and a section of it had chipped out, so it couldnt make enough pressure on the clutches for a good hold. If that is the problem and it is not corrected soon, it will burn up the clutches and possibly some other parts slipping like that.

__________________
Chris
64 190D R.I.P.
80 240D W/617 engine -for sale
82 240D -for sale

I'm going to wait until its a bit warmer to do anything. I'm also not driving the car. This sounds like it could get either expensive or difficult to fix if its not the fluid level. Am I correct in that assumption?

__________________
Chris

82 300SD

Ive never dug into a Benz trans yet, (I will be soon) though my initial impression of it that I've gotten around here is that it does get spendy if you have to open one up. One other thought I had after posting last night, the slippage could also be caused by worn out clutch discs beginning to slip.
I've taken a course on transmissions and rebuilt several domestics, which is where I'm basing this diagnosis on. Even though auto trannies have several different setups and control systems, the basic mechanicals are all the same that actually propel the vehicle (servo pistons compressing different clutch packs in a certain order). 2 basic types are the Simpson and Ravenaux gearsets. Honda interestingly is unique, in that they actually use a modified manual shift trans with solenoid controlled shift forks. I have a trans in my 240 that is doing the same as you describe, only in 4th gear, when upshifting, accelerating normally or hard, or going up a hill it slips. I am picking up another car this coming weekend with a dead trans and plan to tear that one apart to see how the Benz units are built (since that ones already totally dead) and maybe between the two trannies I can make one working unit. We shall see, I'm always open for a learning experiment.

__________________
Chris
64 190D R.I.P.
80 240D W/617 engine -for sale
82 240D -for sale

my 83 300d did the same thing and it was the b2 piston.

round cover on the passenger side.

You have to remove the cross member and lower the tranny as far as possible then push in the round cover remove the retaining ring and cover and the piston should pop out. ( Mine fell out in pieces).

Put in new one, install new oring cover seal, install cover and retainer ring cross member and your done.

Do a search and you will find detailed instructions.

Steve

__________________
85 300d in progress

Hmm, I shall have to look ino that, after I get the other one home though, don't want to tear apart my half working one until I have something around to work with should I discover the need for donor parts.

__________________
Chris
64 190D R.I.P.
80 240D W/617 engine -for sale
82 240D -for sale

Ok, so I finally got a chance to check the fluid in the transmission. I let the car run in my car port for roughly 20 minutes, and then checked the level with it running. The level is low. Reverse still engages fine, d-s-l do not. I know that I had a gotten the fluid up to the proper level the last time, but I have not really noticed any signifigant leakage of transmission fluid. I guess the next step is to top off the transmission fluid, and see what happens. Although, I am thinking that this could be a serious problem if the transmission leaks this much. I guess checking it more often would be the thing to do. But it may have taken serious damage by being run low from time to time.
As a comparison, I checked the oil, and that is midway between the notches on the dipstick. I changed the oil around Nov 1.

__________________
Chris

82 300SD

Today I went out and started the car up, let it warm up, and checked the level of the transmission fluid. I added some, but then I couldn't tell how much was needed. So I sat in the driveway, and worked through the gears. Reverse is still fine. First seems a little bit better, but it still doesn't really seem to fully engage. If I tap the "gas" pedal the car will roll forward like I would expect it to, but if I press it down it still doesn't seem to want to catch.

Someone mentioned the B2 piston. What does this do? Where is it? Can I get to it on an SD without taking the transmission apart?

My plan is to start it up, and check the level tomorrow, after all of the fluid has run out of the dipstick tube.

__________________
Chris

82 300SD

Be sure to check the level after driving the car. It will show low if the temperature is not high enough. You need to avoid overfilling it.

check this link out for b2 piston stuffz


http://dieselgiant.com/Mercedesb2pistonsealreplacementl.htm

they have mad other stuff on there too...

__________________
alimony

Based on that write up it does sound like B2 piston could be the problem with the transmission.

__________________
Chris

82 300SD