30/05/2026
We thought it was the usual story… bottom end knock, had metallic particles from a cam or lifter failure torn the bottom end bearings up?
We stripped down this stock 6.4 SRT Jeep engine and found something we’ve never seen before.
The crankshaft was cracked.
A crack that started at the rear counterweight where the trigger wheel bolts on, and ran all the way through to the number 7/8 crank journal. The crack formed a sharp edge that chewed the bearing apart. That was the knock!
No mods. No abuse. Just a completely stock engine with what looks like it could have been a factory casting flaw that slowly worsened over time.
We’d like to point out this is a very uncommon failure and that in hundreds of repairs we’ve never seen this type of failure before.
Anyone else ever seen a crank fail like this?
