We recently bought a 82 300D that has been sitting for a while, and found out that the reason it was parked is that the tranny (automatic) was slipping a little.

Anyone have an idea what a rebuilt or a good used tranny costs (and where we could get one)? We're up in western South Dakota, and there aren't many Mercedes cars around here, much less a dealership. The car is in the Seattle area, and we will be going out there to get it, so could possibly pick up a tranny while out there.

About $1200 to $1700 with convertor.However with many books I would rebuild it myself.Not hard if you take pictures of disassemble.

Adistco,Germanstar,Ebay does have used ones sometimes.Slipping in 1,or 2nd can be just the B2 piston.Dieselgiant has parts.

you could try www.car-part.com but mercedessource.com is in bellingham only abaout 2 hours north from seattle.
its also not that easy to rebuild. you need alot of types tools. alot of parts in them.

I strongly suggest waiting on rebuilding your transmission. The transmissions in these cars is strongly controlled by vacuum. Slipping can be caused by too much vacuum supplied to the transmission, or too little trans fluid. I would first check the fluid level. To do that you must run the car until the trans is warm. Then stop the car and shift through all the gears, then read the level. These trans are particular to the fluid level. You can also try adding a bottle of Trans-X to the trans. Run it for 100-200 miles then drain the fluid and the torque converter, put in a new trans filter, and see what happens.
As for the vac system. There is a vacuum modulator on the driver's side of the trans that control the vacuum to the trans. You can eliminate that as the issue by unplugging the vac lines that goes to it. It is a black line that comes off a vacuum valve on the injection pump. If you remove all the vac supplied to the trans and get a trans that shifts better then you'll know that the issue is not in the trans.

A nasty filter too will reduce pressure to paks.B1 can be replaced with trans in car.

I am planning on changing the tranny fluid and filter before I do anything else. Thanks for the info on the vacuum modulator, I'll try unplugging that too.

I would love to swap it over to a standard tranny eventually, but for now, I'll try to get what I have working.

These transmissions are pretty tough when they are properly tuned, unfortunetly most mechanics don't know how to tune them properly and just replace them. So don't give up on it too quickly.

A swap to manual is fairly easy, the biggest thing you have to deal with the length of the drive shaft. The manual trans is shorter than the auto so you either have to lengthen your driveshaft or take the one out of the donor car and have it shortened.

If you winde up pulling the pan , you might want to replace the K1 spring too . Google and check the forums at www.mercedesshop.com .

i did a search for the k1 spring but could not find it. what does it do? Why replace it?

dieselgiant has parts and info on the b2 piston.

The B2 piston is involved in the 1-2 shift. The K1 spring is involved in the rest of the shifts. Don't ask me what they do. I don't know.

quote:

Originally posted by biodiesel300TD:
The B2 piston is involved in the 1-2 shift. The K1 spring is involved in the rest of the shifts. Not sure what they actually do though.