Rear Seal Replacement

Q: Rear Seal Replacement

I intend to replace the rope rear main seal in my 1968, 350, with an original type rope seal. All the information I could find on the cheveron/lip type Cadillac seal required pulling the engine and crankshaft to properly install it.

The engine is still in the car and at this time that is where I would like it to stay. My question: Is it possible to drop the pan with the engine in place? I am worried that there may not be enough clearance between the front crossmember and the pan to allow the pan to clear the crankshaft and be removed.

If so are there any tips or procedures that make this possible or easier? The bellhousing and flywheel are removed at this time.

Any advice would be appreciated.

A: The rear seal (upper half) can be changed without dropping the crank by using the new seal and turn the crank by hand. The seal can be rotated out of it’s position, and the new rotated in. But, the hassle you’ll have just getting the pan off isn’t worth it. It’s best to pull the engine and do it right. With the engine out, it’s a lot easier and you can do some other things while you’re in there. Like change all the bearings. These can also be turned out by using a bent cotter pin. Just bend the cotter pin to look like a “T” and put the bottom of the “T” into the oil journal. Then, you can turn the crank and the bearing will turn out with it. Put the new one in this same way. This way you don’t have to remove the crank. Just remember to use engine build lube. This is also a good time to replace that 30 year old oil pump, the heart of your engine (it stops, you stop). I’ve tried removing the pan and doing this on a Camaro with a 350, and I had to drop the steering idler arm, and lift the engine a couple inches just to get the pan off. Even then, things were tight and made changing parts very hard. I finally pulled the engine and finished it right.

A: I can tell you this much…. Yanking the engine at this point would be pretty simple… especially if you can easily disconnect the exhaust system. My guess is that you can yank the engine with about 4 hours of work and two sets of hands at this point. Swapping the seal once the engine is out is only an hour or two (plus whatever else you want to do). If you do it, keep in mind that you can also reinstall your clutch with the engine out and avoid the pain in the butt of remounting and aligning the clutch assembly from the underside of the car. All said, you’re probably about even, or ahead time wise (removing the engine vs not removing the engine)….. And that assumes that you would have had no problems if you did all the work from the underside. If you consider the skinned knuckles, oil in your hair and @#!%$@@ words that go with under car work, I would certainly remove the engine…. But that’s just me. Now that I’m a member of the 40+ gang, (who has false teeth do to hitting himself with a misguided wrench) I try to stay on the top side of the car as much as possible.

A: would go one step further. replace your rod and main bearings along with the oil pump while you have it down. It has been my experience that seals dont start leaking for no reason ….. there is wear there that is allowing the componemt to move and cause the seal to leak.

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