Transmission leak: 91 300TE 4matic - PeachParts Mercedes-Benz Forum

ramonajim · #1 10-21-2010, 11:37 AM

Looking to tap into the collective wisdom and hopefully save some money......

91 300TE 4matic, 162k miles. Started leaking transmission fluid after being overfilled ~ 1 year ago. Minor drip, would qualify as nothing more than an annoyance to me except for the fact that it drips onto the exhaust creating mass quantities of smoke at highway speeds. She served well hauling Ma around town to her doctors, but now is mostly useless if we can't run her on the highway.

Got an estimate this morning. $1,600 if the transmission has to be R&R'd, could be less if he can get at the leaking bit by loosening things up enough to snake his tools and hands in without actually dropping the tranny. That cost includes a complete seal kit install, since his source only sells the complete kit ($220). Looks like Fastlane sells individual seals - so that will be considered.

Leaking bit - identified thus far as "a solenoid, passenger side near the top." Mechanic jokingly suggested cutting a hole in the floor would give easy access and may well be cheapest route. I'm not dead set against the idea myself.....

Questions:

Anybody able to identify the specific solenoid based on the little bit of info I have? Any specific questions to ask to figure out exactly what is the culprit?

Thoughts on the two "non-traditional" approaches:

1) loosen things up enough to get in without removing the tranny - any idea if this is feasible? Something I could do myself (I've swapped Miata engines, done multiple clutches on manual trans cars, but have never pulled an auto trans and don't have a lift)?

2) cutting a hole from above to get access to the solenoid. I'm comfortable pulling seats (if necessary) and carpet and making the hole - should I be? Hidden gotchas to worry about (beyond making dang sure there are no fuel/hydraulic/other lines or wires under my cut lines)?

Thanks in advance!

ramonajim · #2 10-21-2010, 02:53 PM

Update: another conversation with the mechanic to get more details.....

Leak is not from a solenoid, is from a cover plate next to a solenoid.

Figures it'll take a couple hours labor (at $98.62 per) to determine if he can get the plate off & the seal replaced without actually dropping the transmission.

He's not willing to entertain the hole in the floor approach. "Not saying it's a stupid idea, it's just not the kinda work I want to be doing." Fair enough.

His best guess is that we MIGHT be able to get to the cover plate without removing the front seats (may be just behind the passenger side front seat). What I don't know is if we could get the carpet out without pulling the front seats..... any idea?

silversleeves · #3 10-22-2010, 02:09 PM

Have you checked your transfer case fluid level lately? It is possible that the leak is coming from a faulty t/c seal as well.