1974 280C Auto-transmission pan gasket - PeachParts Mercedes-Benz Forum

grubby65 · #1 11-07-2013, 09:53 AM

I changed the transmission filter in my 1974 280C with an Automatic transmission. Has anyone had issues with the gasket sealing. I think of myself as a semi-competent mechanic and I have been having a terrible time getting the gasket to seal. I have acutally tried 3 different times, I have the car front jacked up and on stands. When I put two quarts in the fluid runs out like it is in a sieve. It appears to be such a good and simple sealing system I can't figure out what I'm dong wrong. The grove in the transmission itself is clean, but when I bolt the pan to the transmission it doesn't seem to go in all the way. There is approximately a 1/4" gap between the flat part of the pan and the bottom of the transmission, but the gasket is going up in the grove. The filter and gasket kit I bought was not a Mann it was from NAPA. It almost appears the gasket is a little thick and not letting everything go into place. Any help would be greatly appreciated, I'm about out of Oil dry.
Thanks.

cefalu · #2 01-10-2014, 05:55 PM

Weird, I just changed my '74 280c pan gasket last week and it doing the same thing! Have you figured it out?

joshhol · #3 01-10-2014, 06:51 PM

Best get a Mann or equivalent gasket.

cefalu · #4 01-10-2014, 07:14 PM

I used a Mann filter/gasket kit from Pelican Parts. It seems like it is leaking from the dipstick tube attachment to the pan. Unfortunately the kit does not include new washers at the banjo bolt so I had to reuse my old ones. That is what I am thinking.

rog-o · #5 01-10-2014, 08:09 PM

I had a similar problem on my 1975 300D. I used copper washers from NAPA, part #3877. They were not metric, but they fit fine.

NAPA AUTO PARTS

cefalu · #6 01-11-2014, 04:46 PM

Thanks for the napa part number, I just picked up 2 new copper gaskets, we'll see if that does it.

What worries me, is I am thinking my trans sump is bent. My sump does not look nice and straight like yours. It is bowed in on the bottom like it ran over something. I bet I have a warped sump and it's not sealing. Although it didn't leak before I changed the filter and gasket.

cefalu · #7 01-11-2014, 08:40 PM

I figured it out. The fluid was coming out from under the heads of the two rear 13mm trans sump bolt heads. The front two seemed to be OK. I torqued them down a bit tighter, tighter than I felt comfortable and it stopped the leaking.

I think my pan is bent and it doesn't seal squarely to the trans body.