Need replacement transmission for 87 300TD
 

My 300TD trans has been downshifting at highway speed to third and sometimes second for the last couple weeks. Finally brought it to the dealer for diagnosis. They claim it is the governor, and the trans needs replacement. I'm certainly not going to pay the $7500. they are quoting, and after reading horror stories about Ads..co.com, I don't think I want to chance $1750 with them on one of theirs. Anybody put there have suggestions on where to get a reliable rebuilt one at reasonable cost, or have any experience with places like Aamco?

Thanks, J.G.

I have one that worked fine when I pulled it and replaced with a 5 speed. It needs a front seal as it leaks but worked just fine. $200+ shipping. Might be able to ship it cheap on Greyhound.

If you want to go with a rebuilt, Sun Valley has an excellent reputation. I have not purchased from them but am considering doing so for my 95 C280.

rebuilt remanufactured mercedes benz automatic transmissions

Thanks...I'll let you know. As a second opinion, I figured I'd drop it off at Aamco (right around the corner from me) to let them look it over. They are going to call with their appraisal later today. If it's real bad news, your trans may be the ticket. How many miles does it have on it?...and as for the front seal leak- how tough a repair is it to replace the seal? wish I was closer to ATL...I'd just drive down and get it!

J.G.

I also have a slushbox sitting in the garage from my 300d. It was rebuilt by the previous owner a couple of years ago with receipt. I should probably put it up on CL.

That's also great info...I had not heard of Sun Valley before...2 yr unlimited mileage warranty is pretty good too...

J.G.

Why not pull the governor and inspect it? Maybe the worm gear is bad?

I pulled mine from my 92 300D - is it the same for the '87 300TD?

That's funny...the dealer said they thought "the governor was bad and that meant the trans needed to be replaced!" Is the governor something that can be (relatively) easily replaced by any reasonably competent shop? Does the trans need to come out for this?

J.G.

Here is one of the few threads on the subject:

http://www.peachparts.com/shopforum/tech-help/308281-help-stuck-road-722-3-no-3rd-4th-gear-2.html

If it's the same as the one I did - it's not that bad. You push the transmission to the side and pull the governor cover off and pull it out.

There is a plastic worm gear that sometimes breaks and causes issues with the higher gears.

replacement transmission
 

I have used Sun Valley. I ordered one rebuilt about 6 years ago was a great deal and I am still driving it. was very reasonable for me, was 1.500 and that was shipped to RI from CA. not bad at all. worked great. not advertising here but was the best deal I could find.

Great threads...thanks!! Got some reading to do!

J.G.

if the governor was bad the trans would not shift out of 1st or if it was stuck in an open position it would lock out the lever in N and prevent shifting into R.

Your problem sounds like something the valve body is making it shuttle between the two speeds. I read about this problem a long time ago here on the forums, the person had to partially disassemble the rear part of the valve body and clean out an internal screen. Cant recall exactly what it was.

Try going for the low hanging fruit first: See if you've got a faulty/sticking kick-down switch under the accelerator pedal. Try unplugging it. Also check that the wiring to that switch is not shorting out.

Good luck.

Your transmission will be similar to the one shown here =>

http://www.peachparts.com/shopforum/diesel-discussion/323259-722-303-bits-photo-shoot.html

But I guess there'll be more plastic parts in the back end...