Finally Revealed Rod Knock 91 LT5

[Torchred96]

I've had the short block sitting in my garage taking up space and was about to put it out by the bulk pick up. But before I did, I wanted to see what was causing that horrible knock. Took me a while with hand tools, but finally got the cradle off and surprising saw no obvious damage on the mains or in the cradle bearings. so, I started with the side I was pretty sure the damage was on...left front, and sure enough:

Turns out, #1 rod big end spun a bearing and mains have no obvious damage..in fact look perfect. I will post a picture in a little while, but I guess the block isn't going to the recycler now

I haven't checked 3-8 yet but #2 on the same journal looked fine.. The bearing does look thin..and the engine had about 135k miles and probably run for a long time with a hard miss due to the injectors before I got it so maybe a contributing factor?


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[Torchred96]

Also, I imagine the crank is hurt on #1 as it looks like a lot of metal transfer to the journal from the bearing...but is that a repairable item or is it likely scrap?

[A26B]

Originally Posted by Torchred96

Also, I imagine the crank is hurt on #1 as it looks like a lot of metal transfer to the journal from the bearing...but is that a repairable item or is it likely scrap?

The crank may very well be fine, but would require qualified clean-up & inspection to be sure. LT5 cranks are nitrided steel & really tough. Because of the toughness, used crankshafts don't have much value or marketability. Definitely not trash though:-)

[Torchred96]

Thanks Jerry .I appreciate the feedback.