79 300TD 123 auto trans?

The 79 300TD sedan i picked up has a funny problem with the automatic transmission. The manual on CD I received last week is a Mitchell, nowhere near as useful as a factory manual, but cheap. The transmission, when first put into 'Drive' takes up to a minute to actually move the car, but after the initial morning startup it operates fine for the rest of the day. Fliud level is good, no funny smells, clean and red. What is going on here, servo seals or bands or what?

Reply to
Stupendous Man
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Hey! A problem I have actually encountered and dealt with. I have 2 other vehicles, non-mercedes, which don't want to move on the initial startup just like yours. I do not know what the actual problem is, but while your car is warming up, idling, put the selector in neutral. It was explained to me as this: "the tranny fluid is not being moved around much while in Park, and nothing gets tranny fluid to it to make anything move until the gears are changed. If the tranny is put in neutral whilst warming up, all the fluid is being moved by the internal tranny pump and putting fluid where it needs to be so it can be ready to go." I tried it and it does work (for my 2 other vehicles). The routine I've come to use is that when I first get in the vehicle, I start it, shift it to neutral, keep my foot on the brake, adjust the tilt steering wheel, find the seatbelt and click it, check my four corners, shift into forward or reverse, and go!

Reply to
biodieselbob

Thanks, Bob. This morning i started it up and without my normal waiting for warmup, I dropped it into low and it pulled away instantly. Whatever is wrong doesn't cause problems, I hope. I guess i'll call a transmission specialist I know. Hey, has anyone experimented with processing used engine oil for fuel?

Reply to
Stupendous Man

Then this sounds like valve body problem.

Reply to
Tiger

Reply to
Wan-ning Tan

It seems as though a leaking O ring or seal is allowing fluid to drain back internally somewhere. I drove the car about 400 miles over a few days and it operates normally once I get it moving in the morning and pressure is built. The valve body can be removed once the pan is off, but just replacing it blindly (with what?) is not a good solution.

Reply to
Stupendous Man

Yes, valve body can be removed without dropping tranny.

However, the valve body should be rebuilt by someone who knows all about it... Otherwise, you really need a factory manual and a kit to rebuild it.

Reply to
Tiger

Thanks, Tiger. I am not planning any rebuild. I know there are some places rebuilding valve body and providing exchange. There is one in Georgia, specialized in MB, though I am not sure if my problem is indeed in the valve body.

It is a 89 300TE. The reverse gear needs extra long time to engage. Occasionally it shudders before engagement. But it works fine once engaged. All forward gears work smoothly. I suspect a leaking or sticky seal somewhere hence the pressure could not build up.

When I menti> Yes, valve body can be removed without dropping tranny.

Reply to
Wan-ning Tan

No balls or anything to fall out. In your case, I would say you need a tranny rebuild. It is cheaper to swap a rebuilt tranny than to try to fix repeatedly that will leads to a rebuild.

Reply to
Tiger

Reply to
Wan-ning Tan

In my case I bought the 1979 300SD very cheap (looks and runs great but needs a lot of small things) thinking it would make a good parts mine for my

81 TD wagon, but almost none of the parts I need are the same, so i will be selling the 79 as is once the pink slip arrives. Thanks,
Reply to
Stupendous Man

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