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Mancini Rear Main Cap and Seal Kit

grubby65

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Has anyone used the Mancini Billet Rear main Cap and Seal kit? I have a leak and this is the second time into it, so I would really like to get the leak stopped this time.
View attachment 314720
kind of an interesting design it uses O-rings to seal the cap to the block.
 
My hemi leaked after a total rebuild....changed the seal once with the original cap and it leaked...bought the mancini,machined 12 thou off it..installed in the car....been dry since last summer....very happy. I posted this a while back in case someone had issues...
 
My hemi leaked after a total rebuild....changed the seal once with the original cap and it leaked...bought the mancini,machined 12 thou off it..installed in the car....been dry since last summer....very happy. I posted this a while back in case someone had issues...

Machined .012" off??????
 
hi have a eagle stroker 4.15 crank with stock rear main seal housing, problem with mine is the frigin crank and there stupid knurl . its cut to deep. rule of thumb is knurl=rope seal , smooth = lip seal . herd lots of horror storys with the aftermarket rear seal retainers . i guess its hit or miss so to speak good luck
 
I think Huges makes one to, milling it though?? Mmmm
 
Rear mains leak because the retainer isn't centered. Bolt the retainer to the block with no seal or side seals,measure the side gaps (stack up feeler gauges), they are probably different. Now install the seal and push the retainer back into position with out the side seals or bolts. Remeasure the side gaps, same reading? Probably not. The solution? Drill the retainer holes oversize. Do not use the side seals but fill the side cavities with RTV. I use stock retainers, no leaks, knurled or not. The only Mancini part I checked was for a friend with a leak. It was further off than the factory piece.
Doug
 
Rear mains leak because the retainer isn't centered. Bolt the retainer to the block with no seal or side seals,measure the side gaps (stack up feeler gauges), they are probably different. Now install the seal and push the retainer back into position with out the side seals or bolts. Remeasure the side gaps, same reading? Probably not. The solution? Drill the retainer holes oversize. Do not use the side seals but fill the side cavities with RTV. I use stock retainers, no leaks, knurled or not. The only Mancini part I checked was for a friend with a leak. It was further off than the factory piece.
Doug


Thats a good idea and good to know. I know you hear of alot of rear mains leaking. I used the one from Hughes and it has not leaked any on mine. Ron
 
An experienced Mopar wrench needs to do the install. That's why mine doesn't leak.
 
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What are the two extra long studs in this pic ?
 
I use the stock cap but run a bead of rtv on the inside of the retainer. No leaks.

I'm not sure why, but even the aftermarket companies have retained the knurl on the crank for the rope seal?! My Molnar stroker crank had it!
 
Can that also be a result of not line boring?? Wobbling effect? Just a ? I thought
id get some good opinions on.
 
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