All in - pulling the 4.6 engine and trans to fix oil leaks once and for all

[J.Belknap]

Originally Posted by stunt

Crank snout? Are you referring to the crankshaft hub held on with the "Jesus" bolt that the balancer attaches to?

Yes.

Originally Posted by stunt

If so, what would be the reasoning behind replacing that piece?

If the threads are chewed up. It happens sometimes.

Originally Posted by kesslerbmw

There are motors well over 200k miles with original guides, and there's 100k mile motors that need guides... I'd like to figure out what makes them last longer, or way longer. What's the issue with that?

Different owners driving distances per heat cycle. Different ages. Different environments. I think it's great that you haven't experienced the failure on other motors. In my experience, almost all of the M62 cars that get guides repaired, the tensioner is just fine. Can a bad tensioner wreck stuff? Absolutely. But it's not a prerequisite to guide failure.