Rear main seal leak

[rkiddo]

Has anyone had any success at stopping a rear main seal leak in a 40's 6 cylinder Olds.

[Guest bofusmosby]

Does this car use the old rope seal? If so, I have been told by an old-school mechanic that they can be replaced without pulling the engine. He told me that there was a special tool that was used, by simply pulling the oil pan. I hope he is correct on this, because I also have a leaky rear main on my 37 Pontiac that he will be replacing in the near future.

[Owen_Dyneto]

Yes, assuming it's a graphited cord seal, their replacement w/o removing the engine was a common repair practice in the day. The "special" tool was no more than a Chinese finger toy used to pull the upper seal half thru the groove in the bearing block. The lower half is best fitted into the bearing cap with some sort of mandrel to assure a snug fit. Cutting and trimming the ends accurately is essential, and many makes also used two small wooden strips on the sides of bearing cap for a side seal. Typically to fit the upper half, all the main bearing caps were loosened slightly and equally to allow the crankshaft to drop just a bit. Pretty routine job.

[Guest bofusmosby]

The "special" tool was no more than a Chinese finger toy used to pull the upper seal half thru the groove in the bearing block.

Funny, that's exactly what my mechanic said about the Chinese finger toy!

[Guest Bob Call]

I had an uncle that was an old school mechanic/blacksmith/welder. Many times I saw him take a piece of rope seal and like the seal was a needle he would stick a length of "baleing" wire through the seal like thread and bind it over and crimp it down. He would pull the old seal out by grasping one end with needle nose pliers and while rotating the crankshaft pull the seal out. Then he would thread the baleing wire in the seal groove and around the crankshaft and pull the the rope seal through and then trim both ends of the seal with a sharp blade leaving a little sticking out below the block to make a good contact seal with the part of the rope seal in the main cap.