Rear main in wrong? (Pictures)

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dgibby

dgibby

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Obviously one is in wrong since they are not in the same..
which way is correct?

67B42478-666C-417A-A16C-ECDDB31522D9.jpeg


4F743F1E-B092-452A-BC15-7163AD3533C7.jpeg
 
The Second picture, the one in the block is wrong, it's in backwards! The second thin lip is just a dust/dirt seal. Rule of thumb is the lip faces the oil.
 
The piece in the block is incorrect.
 
I guess I am not seeing that...LOL

they both are in the block..
 
I could be wrong but I would think "knife esge" facing in?
Put one 1/2 one way and the other 1/2 opposite?
 
The 1/2 with no crank, is correct. Look at the fine angled ridges. They direct oil back into engine.
 
Thanks everyone.
Figured the one in the block was wrong but figured I’d double check.
Any tips for the install of the new one?
 
dgibby said:
Thanks everyone.
Figured the one in the block was wrong but figured I’d double check.
Any tips for the install of the new one?
Click to expand...

I put a thin bead of RTV silicone around the groove before I put the seal, install the seal and wipe off the excess and install it before the silicone is fully dry/cured so it conforms to the seal... That way it will keep pressure on it as it wears...
 
I use engine assembly lube...and lube the seal and then install it...and put a dab of sealant between the block and cap at the seal ends......no runs ..no drips no errors....
 
I always staggered mine so the ends weren't flat with the machines surface areas, that way a piece of each end slides into the cap and block. Does that make sense?
 
Matts440 said:
I always staggered mine so the ends weren't flat with the machines surface areas, that way a piece of each end slides into the cap and block. Does that make sense?
Click to expand...

I put my last 360 together with the seal even with the cap mating surfaces. Never had a leak from it.

My dad helped me assemble my new engine and he INSISTED that I had to stagger the seals. He is a licensed, trained, certified mechanic. Has been working on diesels the last 15 years mostly freightliner, but was a regular auto mechanic for years prior. I ended up doing it his way against my will. Hopefully it doesn't leak.
 
what all says. offset both top and bottom. point r urebulding (sp) no stop. if you and you are doing screw all others lip on seal should b in to motor pressure comes out of engine keep it in. but b slow offset each seal. that makes the seals covering main meeting area solid not much a 1/4 inch no leaks on loose engines. in other words have part any amount sticking out of block offset man same . then u have a solid blocking oil...
 
I cannot begin to count the number of rear main seals I have installed through the years, be it in new builds, or maintenance repairs, but I have never one time offset the rear main seal. I think that is some bullshit magazine myth. If the rear seal joint is going to leak, it's going to leak no matter where the joint is clocked. Also, I always put a small dab of high temp RTV on the ends of the seal and along the mating surface of the block where rear main bearing cap meets it. Has always worked and been leak free for me.
 
charles mill said:
what all says. offset both top and bottom. point r urebulding (sp) no stop. if you and you are doing screw all others lip on seal should b in to motor pressure comes out of engine keep it in. but b slow offset each seal. that makes the seals covering main meeting area solid not much a 1/4 inch no leaks on loose engines. in other words have part any amount sticking out of block offset man same . then u have a solid blocking oil...
Click to expand...
Is it just me or do I need CC on this reply?
 
RustyRatRod said:
I cannot begin to count the number of rear main seals I have installed through the years, be it in new builds, or maintenance repairs, but I have never one time offset the rear main seal. I think that is some bullshit magazine myth. If the rear seal joint is going to leak, it's going to leak no matter where the joint is clocked. Also, I always put a small dab of high temp RTV on the ends of the seal and along the mating surface of the block where rear main bearing cap meets it. Has always worked and been leak free for me.
Click to expand...

There is nothing wrong with installing them flush, and tons of people have done it that way for years as well as the manufacturers.
Offset ends is just an extra measure to be sure the lip of the seal halves is exactly lined up with each other.
If the seal ends are at the parting line of the block and cap there is a chance that parting line may not hold the seal ends exactly lined up.
It's just one of those (just in case measures).
 
TrailBeast said:
If the seal ends are at the parting line of the block and cap there is a chance that parting line may not hold the seal ends exactly lined up.
Click to expand...

I don't think that's even possible. The seal halves protrude what......maybe 1/16 of an inch? Probably less. IMO, there's no way those seal ends can mis-align. There's just not enough seal end sticking out to do it.
 
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