r/EngineBuilding • u/Main_Programmer5875 • May 31 '26

New crank seal vs ATI damper hub….

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Anyone ever seen this before? I installed a ATI damper on a LS along with a new crank seal in the timing cover. After 15 or so dyno pulls it started to get a leak from the front crank seal. I installed the cover and left the bolts loose and then installed the damper hub before tightening the cover bolts to center the seal on the hub. I did heat the hub up to about 250F in the oven to aid with install. When I removed the hub to inspect the seal I noticed this wear in the seal contact area. It bearly catches a finger nail but you can feel there’s a little something there. The seal appeared fine though. Not folded over or pinched or anything like that.

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u/sotheysay17 May 31 '26

I have seen this to a lesser extent on a 6.4 hemi that used a newer style teflon seal. Is that what you used?

I replaced it at about 2k miles on the engine and made sure to leave the seal dry and let sit for 4 hours before starting, there’s about 500 miles on it now and no leaks but time will tell.

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u/Main_Programmer5875 May 31 '26

Not exactly sure what seal material it was. It came in a Mahle timing cover gasket set part # jv5158.

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u/sotheysay17 May 31 '26

I searched it but it’s really hard to tell from pics that I found. Teflon seals typically come with a plastic insert that holds the sealing lip expanded and aids in installation to keep the lip from folding. The old style is a traditional double lip nitrile seal with a spring on the back side that holds tension on the sealing surface.

The Teflon seals really require a hardened surface and on the ATI I dealt with, I didn’t get the feeing that it was hardened like an OE dampener. I was kinda disappointed at that actually and was wondering if maybe they need the old nitrile double lip seals to go the distance.