tranny question - PeachParts Mercedes-Benz Forum

AdrianGT · #1 01-07-2008, 08:20 PM

hey I'm new to the boards and rather enjoy the 80' 300D i bought.
the tranny sips in second and the shifter's really lose.
i was going to have the tranny rebuilt but i recently found a 300TD at the junk yard and with an upcoming sale at the yard i could pick up the tranny cheap.

my question is what can i look for on the tranny to test it's condition on it if any other than driving it. and how much work is it to pull and install? also will the TH tranny work on my 80' non turbo car?

Biodiesel300TD · #2 01-07-2008, 11:17 PM

I wouldn't condem your transmission just yet. Have you checked the fluid level. These transmission are picky about fluid level. If you know it's got enough the right amount. Have you changed the fluid and filter. This can sometimes make a big difference.

kerry · #3 01-08-2008, 08:54 AM

I agree. There are a lot of things to check out before condemning your transmission. First off, remove the vacuum line from the modulator completely and see if the transmission firms up. If so, your problem could be simply a vacuum adjustment.
Do a search on transmission vacuum adjustment and flaring. Also search on Superior kit.

blkntancj · #4 01-08-2008, 11:52 AM

X2 on the vacuum check. My '81 shifted like crap when I got it, found out the transmission vacuum dashpot was missing. Replaced it and it shifts really nice now.

dieseldan44 · #5 01-08-2008, 11:57 AM

another vote for vac adjustments!

And if your shifter is really loose you should change the shifter bushings. I dont know if it will change the shift quality but it will firm up the shifter for sure.

tobybul · #6 01-08-2008, 12:23 PM

beating the subject to death..........

check vacuum... tranny sensitive to vac leaks... remove EGR.... adjust modulator if necesary...

MB tranny's do not crap out that easy.... crappy tranny usually caused by bad controls (vacuum)...

on the 300D - chk the 3/2 lever (there's only one)... mine was broken and when I replaced it, it fixed the shifting problem (slipping on 2nd)...

AdrianGT · #7 01-15-2008, 11:17 PM

well i got the 2 vac leaks fixed. one's to my trunk so i dunno if i'll ever get that thing open without cutting the trunk open =/ but that's another problem. if i floor it it will shift into second slowly, then right to third within 5 or 10mph and then third will flare unless i put it in "S" .
also my tranny leaks quite a bit, I've had to put a quart in it already and there's a spot on the street in front of my house

Knightrider966 · #8 01-15-2008, 11:26 PM

Quote:

Originally Posted by AdrianGT

well i got the 2 vac leaks fixed. one's to my trunk so i dunno if i'll ever get that thing open without cutting the trunk open =/ but that's another problem. if i floor it it will shift into second slowly, then right to third within 5 or 10mph and then third will flare unless i put it in "S" .
also my tranny leaks quite a bit, I've had to put a quart in it already and there's a spot on the street in front of my house

Put in some Lucas brand Transfix. It's a lot thicker than tranny fluid and it does help to rejuvenate your transmission seals.

It won't stop the leaks, but it will slow them down.

AdrianGT · #9 01-16-2008, 03:38 PM

Quote:

Originally Posted by Knightrider966

Put in some Lucas brand Transfix. It's a lot thicker than tranny fluid and it does help to rejuvenate your transmission seals.

It won't stop the leaks, but it will slow them down.

already got some in there

VWGuru&BenzFan · #10 01-16-2008, 09:27 PM

Before you call kaput on the transmission, follow the advice here. Welcome to the Orange County W123 club, by the way.

charmalu · #11 01-17-2008, 12:34 AM

Quote:

Originally Posted by AdrianGT

well i got the 2 vac leaks fixed. one's to my trunk so i dunno if i'll ever get that thing open without cutting the trunk open =/ but that's another problem. if i floor it it will shift into second slowly, then right to third within 5 or 10mph and then third will flare unless i put it in "S" .
also my tranny leaks quite a bit, I've had to put a quart in it already and there's a spot on the street in front of my house

www.peachparts.com/shopforum/showthread.php?t=194141

check this out for getting into your trunk.

Charlie

kerry · #12 01-17-2008, 09:44 AM

Search on transmission vacuum adjustment. There's a very good long thread on the topic. Apart from the leak, your transmission shows all the symptoms of an out of adjustment transmission. The Bowden cable can also be adjusted to modify shift points.