Found a great looking 300CD, one problem. - Page 4 - PeachParts Mercedes-Benz Forum

nickofoxford · #46 07-19-2009, 05:55 PM

Well guys, I got the CD towed out to the family mushroom farm on wednesday. So far me and one of my buddies have managed to change the transmission fluid and filter to no avail. Then we changed the fluid again with draining the torque converter, no dice. I took the linkage off the transmission and turned it by hand from underneath the car (car on blocks) Nothing in any gear other than the park pawl working in park.

One thing I noticed, is that when I would give it a quick burst of throttle it would kick the tire in the right direction for the gear it was in, and then nothing. My friend tried to hold the tire still and it really kicked but then almost instaltly lost all power. At idle in gear, the tire would jerk like the second hand on a clock, but it was extremely weak. This was all done with just one of the rear wheels jacked up off the ground.

Maybe a fluid pressure problem?

When I dropped the pan I found there was a tiny ammount of grey silt on the bottom of the pan, I don't think this is a huge problem is it?

The filter looked like complete $h*t. When I replaced it with a new one, it changed nothing. Another thing I noted was that the pan gasket was at one point sealed with a black silicone caulk (or something of the like) and small chunks had found their way into the transmission. I found a couple little bits on the valve body and a large chunk inside the suction side of the filter.

Is this transmission worth tearing down or should I just replace it? Im not too concerned about the ammount of work.

nickofoxford · #47 07-19-2009, 06:11 PM

This just struck me, could a catasrophically failed modulator do this? I read somewhere that the vacuum modulator controls the working pressures in the transmission, if the spring in the modulator or something in it were to break, could the modulator kill working pressures?

tankdriver · #48 07-19-2009, 07:05 PM

My understanding (definitely limited) is that the modulator going bad would result in shifts that bang into gear, but it would go into gear.
I'm surprised no one has thrown out the B2 piston failure yet. Does it go into Reverse?

nickofoxford · #49 07-19-2009, 11:47 PM

Quote:

Originally Posted by tankdriver

My understanding (definitely limited) is that the modulator going bad would result in shifts that bang into gear, but it would go into gear.
I'm surprised no one has thrown out the B2 piston failure yet. Does it go into Reverse?

Thanks for the clarification, it won't go into reverse either.

charmalu · #50 07-20-2009, 12:28 AM

At the begining of this thread some one asked about shifter bushings, did you look at them to see the condition of them? I just scaned through the 4 pages, and don`t see mention of them.

Charlie

nickofoxford · #51 07-20-2009, 01:50 PM

Quote:

Originally Posted by charmalu

At the begining of this thread some one asked about shifter bushings, did you look at them to see the condition of them? I just scaned through the 4 pages, and don`t see mention of them.

Charlie

I checked them and they're loose but the linkage will sill engauge every gear and even set the park pawl, so they can't be too bad.

carnut · #52 07-23-2009, 03:09 PM

I THINK THE REAR END IS BROKEN. REMOVE THE REAR COVER, INSPECT RING GEAR AND PINION OR CHECK IF ONE OF REAR REAR DRIVE AXLES HAS A SHEARED CV JOINT.

nickofoxford · #53 07-24-2009, 05:34 PM

Quote:

Originally Posted by carnut

I THINK THE REAR END IS BROKEN. REMOVE THE REAR COVER, INSPECT RING GEAR AND PINION OR CHECK IF ONE OF REAR REAR DRIVE AXLES HAS A SHEARED CV JOINT.

I'll have to check that out. Do you know if the rear end could slip? I jacked the whole rear end of the car up and spun one tire and the other rear tire on the other side would spin the other way. So I thought the rear was good. But maybe im wrong?