I have installed plenty of rear seals on 1st gen motors and all have taken a hammer and a fair amount of effort but I recently install one on my 04 truck 6.0 and I was literally able to push it in with only my fingers. I bought another brand seal from a another supplier and installed it and it went in just as easy. The first seal was a GM seal. Is this right?

 

I'd be curious of this as well, I'll be doing mine in a week, but won't know until I'm in there, so anyone's input would be obliged.

 

It's REAR main seal.

You're better off replacing the entire rear cover. GM part number 12639250 gets you the cover, gasket, rear main seal, and bolts. Guaranteed not to leak.

 

Thanks grammar **** but what I really was asking is this the way the REAR main seal is designed? I have seen a few post where guys have mentioned that the rear seal goes in real easy but for it to push in all the way with just finger pressure seems wrong. This is a low mileage 6.0 and the old seal seemed to be in there like a normal old stlye sbc (took a hammer to get it out.) The engine is already installed in the my truck so I'm not really wanting to swap the entire rear cover.

 

Ford seals are the same way. Old fashioned style seals have a metal lip, and the outside seal is metal on metal. That's the kind you pound in with a hammer and a block of wood.

New style seals have a rubber lip, and the outside seal is metal against rubber. Those are fairly easy to press into place with your fingers.

 

http://www.ls1gto.com/forums/showthread.php?t=275886

https://ls1tech.com/forums/tools-fab...all-tools.html

 

The entire cover solves ALL issues, including any type of problem you're experiencing with the seal installing too easily. Furthermore, replacement of the entire rear cover involves the same amount of work for access as replacing just the seal: flexplate removal.