rear main seal
 

i've got a 5-cylinder 617 engine in my 209d van. the rear main seal is leaking and i'd like to replace it. i wonder if this is something that i can do with the engine in and just pull the transmission or if the engine needs to come out. also, are there any special tools needed to do this? thanks, and happy holidays!

-eric

Welcome to the Forum.:)

From what I have read here on the Forum, and in the FSM, the engine has to be pulled. the crank has to be removed.
The rear seal is in 2 pieces. It is a rope seal, 1/2 fits into the block, and the lower 1/2 fits into a goove in the upper pan.

A little more that a weekend R&R.

Charlie

You'll need to pull the engine to do the top half. I'm not sure about the bottom half. If may be possible to pull the pan with the engine in the van and replace the lower half of the rear main seal.
Are you sure it's the rear main seal and not either the valve cover gasket or the oil filter housing gasket?

By the way, got any pictures of the van you can post. Not many van owners on here.

There are threads in here where people have done it without pulling the crank out. In fact I want to say that they didnt even take the engine out of the car!

How'd the upper pan get pulled out of the car with the motor in? I thought it was impossible to remove in the car... a van may be different, I don't know. If I remember correctly, it's a two piece seal, so possibly the old one could be removed by pushing it out with the new seal... Hmmm.

There was a thread within the last six weeks or so with pictures of a rear main seal being installed on an engine on a stand.
I can't remember my vans enough to know if the upper pan is removable with the engine installed.

Here it is:

http://www.peachparts.com/shopforum/diesel-discussion/288644-fitting-rear-crankshaft-seal-om617.html?highlight=rear+main+seal

You might want to PM Army to get his opinion on the possibility of installing it while the engine is in the vehicle.

IIRC you dont need to pull the pan just get enough room around the crank to get the seal in. My memory is fuzzy and this is like 3rd hand info but there is a few threads on it...

I've only done this with the engine out.

Even with the engine out it is best to fit the seal in the engine block (this sits above the crankshaft when the engine is in the car) without the additional restriction of the mating plate that goes between the gearbox and the block. When in place this mating plate makes it hard to cut the seal to length.

http://www.peachparts.com/shopforum/...1&d=1290628309

http://www.peachparts.com/shopforum/...4&d=1290084591

http://www.peachparts.com/shopforum/...3&d=1290628325

Furthermore to get the seal to fit properly you need to push it in really well - lots of rolling force needed here. You would definitely need to remove the crankshaft to fit this upper seal.

For the lower seal that fits in the upper oil pan - well I guess you could remove that with the engine in place. I guess that was done on my car with the following result:-

http://www.peachparts.com/shopforum/diesel-discussion/273825-om617-front-crankshaft-seal-nightmare-should-i-re-align-upper-oil-pan.html

I think you've got to be really good to get it right otherwise you'll get leaks all over the place - you need to use a RTV type sealant between the upper oil pan and the block.

Also I'll give this WARNING:-

I have been told by an engine builder here in the Netherlands that if this seal is incorrectly fitted it can cause a lot of localised heating which can in the extreme kill crank main bearings. See post #20 in the thread above.

(Don't shoot the messenger I'm passing on the info!)

Good luck

(Here's a W123 OM617 (non turbo) removal thread if it helps:-
http://www.peachparts.com/shopforum/diesel-discussion/289886-how-i-took-out-my-1981-w123-300d-euro-non-turbo-engine.html
)

EDIT:-

After thinking about it a bit more - I think you'd probably have to jack up the engine a bit to get the upper oil pan out. The cross member under the engine on a W123 would probably get in the way - as would the motor shocks. I don't know what the set up is like on your van but I guess it won't be too dissimilar. This would involve undoing the engine mounts which in my opinion is probably the only sticky point on an engine removal.

I think you could spend a lot of time trying to get the upper oil pan out with the engine still in the vehicle - a lot of grazed knuckles and a lot of swearing. Although it may seem like more work I'd go down the engine out route and save yourself a lot of hassle.