Transmission leak 300E

I noticed that a leak of transmission fluid has started on my 300E. It appears to be coming from the passenger side of the transission and it is evident at the spot where I park my car. It is not serious but I would like to fix it. Anyone knows which part of the transmission it is coming from? It ir really difficult to point it out since the whole right side seems to be oiled up. Thanks for any help.

Dear Mr. public enemy,

Someone is going to have to clean the oil off of the fouled transmission and then re-examine it after a hundred miles or so. There are many places for oil to leak from a transmission: pan gasket, pan seal plug, cooler lines, B2 piston cover, etc. If anyone tells you where the leak is coming from over the web, they are either psychic or just plain guessing.

The cost of repair will depend on what exactly is leaking. If it's the pan and you need a transmission service anyway, the leak is fixed for free when they replace the pan gasket. If it's something harder to get to, you may have to live with the leak or pull the transmission out.

Good luck. HTH.
someguyfromMaryland

[tgrand]

Dear Mr. P.E.

Speaking only from experience with my '88 300E, I had a leak on the passenger side that was coming from a dried up O-ring way up on the side of the transmission. I believe my mechanic called it the secondary pump or something like that. Anyway if this is the problem, you have to lower the back end of the transmission to get to it. My leak only got worse.

tgrand,

Did you ever get the secondary pump o-rings replaced?

Has any DIY'er done this job yet? How many hours does this job take?

Jeff

[tgrand]

jfujimoto,

I did have them replaced about a year ago, didn't do it myself though. The o-rings are about the diameter of a 50-cent piece and are very cheap but the labor was 3-4 hours if I remember correctly. My old o-ring(s) was dry and brittle, like I said earlier the leak only gets worse if this is the source.

I hope that I don't get flamed for this buuuut.. If it is a o-ring that is leaking would it not be ok to try some transmission stop leak to see if that would correct the problem?

starfighter,

The labor hours for the O-ring R&R is about 8 hours (so says the local MB dealer)! Whoa!!!
I'm not going to spend that much money if I can do it myself. Anyway, I was also thinking about the tranny stop leak products or just keep adding fluid like LarryB said in other posts. Cheaper to add a quart than pay the dealer. But I'm not sure on the longevity of the O-rings at this stage. It leaks about a tablespoon each day.

Force be with you,

Jeff

yep that is kinda expensive I think I would try the stop leak additive.Boy I tell ya though I really hate a leaky car I find it embarrising when you have a prety car and it leaks it just makes it look cheap. but anyway good luck with what ever you decide to do.

[joel]

just a word of caution, this happened to me last
summer. parked the car and attended a wedding
reception with my wife in formal attire. went back
to the car 10 mins. later to pick up our gift i left.
all ATF fluid was ozzing on the floor. had the car
towed with all the hazzles attending to it.

thank God it happened while car was parked.
can you imagine if it happened when the car is in
motion. the ATF came out like an open faucet.

moreover, a week after it was fixed. i have to have
wheel alignment and balancing. why? the tower just
lifted the rear end the car, hence, the front end had
a lot of stress. on a friday night, piggy back tow
trucks are hard to find. when it rains, it really pours!

and the lesson is ............!

[tgrand]

Just my 2-cents.

8-hours to R&R ouch!!!! My labor was 3-4 to drop the back end of the transmission to gain access to the secondary pump, and I have some corrosion from New Orleans on the nuts and bolts which added .5 hrs or so. I also discussed the stop leak and because of the tight tolerances and such was strongly advised to stay away from dumping goop in the transmission.

tgrand,

Yeah, I am hesitant about additives. My mechanic friend suggested a neighborhood tranny shop. I'm gonna talk to the owner and try and get a better deal because I'm too frugal. The thing that worries me is when and if the o-ring decides to totally crap out. I wouldn't want to end up like Joel.

Jeff