Classic/Antique Car Repair: Rear main seal, torture method, main bearing cap

Question
Dick, After finally getting my'49 Packard drivable (Thank you), I discovered that the more I drove it the more my rear crank seal leaked oil.  I got to the point where I was losing about a quart in sixty miles of driving.

Now that the weather is on the verge of warming up again here in Indiana, I'd like to replace the seal.  I've looked at some ways to do it, including the factory manual.  Dropping the crankshaft looks daunting.  What do you think about the little "Sneaky Pete" type tool?  That's the one with the "Chinese finger" that you grab the wick seal with and pull it through, over the top of the crankshaft.   

Thanks in advance.

Answer
These always seep some, but your case seems to be much worse than you can tolerate.  

If you are certain it is coming from the rear seal, my advice is to drop the crankshaft slightly so as to make it easier to insert the new seal, using the Chinese finger torture method. I have done it that way on my cars, and it usually makes some improvement in the leak rate, but don't expect miracles!  

To drop the crankshaft is not all that difficult - just loosen all of the main bearing cap bolts a couple of turns and let it come down a fraction of an inch.  

If your car has automatic transmission, though, this is not a good idea because it puts a lot of stress on the front bearing and seal in the Ultramatic.  

If you have a manual transmission, this is not a worry.  

After you loosen the bearing caps, install the new seal following the instructions regarding trimming the ends, and of course put the lower half into the rear main bearing cap.  

While you have the bearing caps loose, it is a good time to do a Plastigauge test of bearing clearance on a few of the bearings, to make sure you are not due for a lower end refurbish.  The rear seal leaking may be the result of excessive bearing clearance.  

Of course if you have excessive bearing clearance, it is time for an engine rebuild anyway,it's time to pull the engine out, and with it out of the car, it is much easier to work on the bottom end of the engine; you can do a much better job of installing the rear main seal.  Even with that, it will probably always be a dripper - the only Packard that doesn't drip oil is the one that is out of oil!

Dick