56 365 Replacing rear main seal in the car

[dplotkin]

Anyone managed to install a new rubber rear main seal with engine in car?

Dan

[Dave Shepherd]

Dan this can be a torturous job, the issue is getting the crank to drop down enough to do this. Plus if the seal surface on the journal is knurled  the modern seal may not work.  I would suggest tryig do loosen the fluid coupling from the crank for more movement.

[Roger Zimmermann]

Yes, I did it on two cars, without lowering a lot the crankshaft, because the bolts from the first bearing cap are too near from the frame. If you are careful enough, the upper seal can be inserted without problem. Just don't apply pressure on the lip; if you do so, you will have a leak.

[dplotkin]

Thanks. I'm leaking pretty good, can't go much longer like this. I ordered a new rubber seal from Terril Machine in TX.

Dan

[Walter Youshock]

Get the rubber seal.  I did my '57 and it was no problem.  One thing I did was offset the seams about 1/4".  Hasn't leaked a drop.

[RobertM]

This is an excellent step-by-step how-to replace that seal:
http://midcenturycadillacs.com/index.php?topic=23.msg73#msg73

HTH! Bob

[dplotkin]

Excellent, thanks

Dan

[Raymond919]

"One thing I did was offset the seams about 1/4"." 

Walter, I'm following the instructions for learning purposes and don't have a problem on my car ( a '49 ). I'm not sure what seams you're referring to. Could you enlighten me?
Thanks,
Ray Schuman
#26141

[Walter Youshock]

The seal is in 2 pieces.  I installed the top half where part of the seal hangs down about 1/4" on the driver side and is conversely 1/4" up in the top bearing on the passenger side.  SO, when you install the lower bearing, the offset seams will be inside the bearing housings rather than level with them like the rope seal would have been.  It lessens the chance of leakage at the seams.

[Raymond919]

Many thanks, Walter. Although I don't expect to actually do this myself, I'm now a 'more educated consumer'.
I appreciate the explanation.
Ray Schuman
#26141