Several weeks ago I found the Xmission pan gasket leaking on my 2001 320. I tightened thesix #30 torxs, and it stopped. It leaked one more time, I re-tightened again. It stopped. It started again yesterday, maybe 1/8 oz. on the garage floor.I am afraid to tighten anymore. The car only has 17k miles on it. What should I do? Hate to change out the gasket and fluid for this small leak.

Ron

 

Hi,
First step is to decide where it is leaking. i.e. The sump gasket or the seal used to seal the electrical connection?

Both are easy to replace and not that expensive.

Problem is that if you drop the pan for a new gasket you will need to reuse the existing oil (not good practice) or use new MB oil expensive £8/litre and you will need 3 litres.

If you use new oil you will also need a new filter.

DO NOT OVER TIGHTEN THE SUMP BOLTS!!! should be about 8 lbs/ft.

Sure the trans is NOT overfilled. This tends to cause the gaskets to be more prone to leakage.

Stuart

 

Thanks for the reply, Stuart. It is definitely the sump gasket. The fluid seems to come from were the sump bolts are on the passenger side of the sump. I did tighten 2 of them again today. I do not have a torque wrench, so I really don't like the "fix", but it seems to stop the fluid, for a week or so. I know thatI cannot keep this tightening up, as I make break a bolt. Fluid has never been added, nor has any light ever come on indicating a high level. This all just started a few weeks ago.

Ron

 

Ron,

Tightening the "sump" bolts doesn't actually increase the compression on the sump gasket. The sump gasket is compressed by a "finger" cantilevered from a post spacer which in turn has a bolt running thru it into the gearbox casting. The bolts DO NOT pull down directly onto the sump pan like you might expect. Tightening is unlikely to effect any improvement unl;ess of course they are only finger tight or even looser!

The oil may appear to come from the sump gasket but since you have stated that it is on the passengers side (i.e. RHS in the USA) this happens to be the side where the electrical connection is sited.

I feel like betting with you that you will find that the oil originates from the big round electrical connection and then seeps down to the sump gasket level and fools you into thinking that that is where the oil is coming from, when it isn't. There is a small heat shield attached to the forward RH sump bolt. Remove the shield and wash the area off with degreasant and water. Then go for a good trip and see what happens. If it is coming from the electrical connection DOUBLE CHECK the trans fluid level before going any further. Fluid level needs to be checked by MB unless you make your own. Bazzle posted instructions recently.

Both the sump (ribbed rubber) and electrical connection seals (nitrile "O" rings X2) are pretty robust but I suspect the electrical connection doesn't like being below the oil level permanently.

Come on....I'm sure that you will confirm that it isn't coming from the sump gasket if you follow my post.

regards,

Stuart

 

I'll try it Stuart, but it sure looks like it's coming from the gasket. If it is coming from where you said, how doI stop it?

~R

 

Check the oil level is correct AND change the electrical adaptor which will replace the sealing "O" RINGS. Not very expensive

 

http://www.benzworld.org/forums/r170...t=transmission
and http://www.mbworld.org/forums/showthread.php?t=186733

Bazzle

 

Thanks Baz.
Stuart

 

Thanks Stuart and Bazzle for info. Right now it is still dry of fluid in that general area. As soon as I see fluid, I will check it out and let you both know whatI find.

~R

 

Stuart,on3/25/07 the area around the Xmission pan was dry of fluid. It has stayed that way until 4-11-07, when I found about 1/3 oz. or lessof fluid on the floor. I put over 1000 miles on the car during that period. Again,I checked the same area. The pan and gaskethad fluid on it on the right side. I removed the heat shield near the electrical spacer and connector and felt for fluid. It was dry, with no fluid, not wet at all! Should there not be fluid there, if is leaking down on the pan and gasket?

Ron