I have to replace the rear main seal on my 70 455 due to oil leaking and ruining my clutch/pressure plate. I've been wanting to repaint the engine because I'm not happy with the color anyway so I'm going to pull the engine to do it all.
I know I'm going to remove the main bearing cap once I get the engine on the stand. My question is, should I fish the new rope seal in then or should I loosen all of the crank caps so I can lift the crank to make it easier to get the upper half fished into place? Or is this just asking for trouble?
I'm using a Best Gasket graphtite rope seal.
Thanks,

 

If you are pulling the engine lift out the crank and replace both halves of the seal, you may regret it if the seal develops a leak after it is all back together.
Roger.

 

i would use the rubber 2 piece seal. much less likely to leak.

 

Of course, at that point, you MIGHTASWELL check (and replace) the bearings...

 

Roger,
I fully intended to replace both halves. I was just wondering if loosening the other bearings would allow me to lift the crank a little to make it easier to get the upper half of the seal in place.

jensenracing77,
I already have the graphtite rope seal and I also just put one in my TA's 400 and it seems to be doing ok. Plus, I don't want to have to pollish the crank like you do if you use the neoprene seal.

Joe,
Yeah, this engine has run flawlessly for 10 years aside from the small leak. The thought of doing something that could wreck it scares the H3ll out of me. I wouldn't even know how to tell whether the bearings were bad unless there were as bad as the ones in the TA. They were worn all the way down into the copper. I was told that was pretty bad. It had multiple very bad rod knocks. I found a 1/8" chunk of crud stuck in the oil filter bypass passage allowing oil to bypass the filter ALL the time. Engine only had 14K on the "Jasper" rebuild.

Anyway, I just want to stop the leak with out causing other problems.
That said, I have the chassis manual and can look up the torque specs for the bearing caps but I'm still worried taking the bearing caps off and putting them back on will change something.
As for the bearings, what if they did look worn? What then? Go back with the same size bearings or plasti gauge them and get a different size? I really don't think I'm qualified to make that decision. I've only rebuilt one engine before and my machine shop guy made all those decisions.. That engine only has about 300 miles on it. So far so good......

I really appreciate all the input.