scharpp

uggg dang it, all that work, now I see the rear main has a leak in my 55 324, guess I should have replaced it before installing the engine, is it possible to change rear main seal without pulling the engine, I know on a chevy s/b you can, my luck its not, Thanks

Ozzie

After removing the oil pan and the rear bearing cap, you will be able to "pack" the upper half using a tool (like a punch) and replace the lower half with a new segment. (It uses the "rope" type seal.) The tool BT-12 is used to form & seat the lower half in its recess in the bearing cap. If done carefully it will work. I have done it. If you want to see some photos look at pages 8-15 and 8-16 in the 1955 Oldsmobile Shop Manual. In order to completely replace the upper half you would probably need to lower the crankshaft some. Careful trimming of the two halves is crucial. Also, there are two small cork seals used adjacent to the cap (one on each side) before the oil pan is replaced (fig. 8-29, on page 8-16 in the shop manual). These are usually provided in a gasket set. Cement is recommended for the cork.

scharpp

Thanks Ozzie, I did see that in the manual, but didnt know it could be done without pulling the motor, this is good news, mechanics at my shop said give it a bit, the rope seal may swell now that the motor is running as it has sat along time, guess time will tell, at least now I know I dont have to pull the motor, thanks again

Ozzie

The mechanics may be right about giving it some time. ??? The new oil and heat/activity may help. Time will tell. While you may be able to get it without removing the engine, removing the oil pan "in place" is always a "bear" of a job which I always dread. Waiting some and hoping for the best could be a good investment.

Tedd Thompson

It can be done, (had mine done that way last time also) but you have to be some kind of contortionist, you flat run out of room between trying to get the pan out of the way ,which if I remember correctly can't be removed completely and then drop the crank enough to slip the top half of the main seal in (I used a neoprene seal) very tight quarters.I don't do tight quarters anymore but my friend who is very talented said lets not do this again....Tedd