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View Full Version : Finally Revealed Rod Knock 91 LT5


Torchred96
11-28-2015, 02:59 PM
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?
http://i1096.photobucket.com/albums/g328/sirlancair1/20151128_164155_zpsgybpy1a9.jpg (http://s1096.photobucket.com/user/sirlancair1/media/20151128_164155_zpsgybpy1a9.jpg.html)
http://i1096.photobucket.com/albums/g328/sirlancair1/20151128_164111_zpsixptgpun.jpg (http://s1096.photobucket.com/user/sirlancair1/media/20151128_164111_zpsixptgpun.jpg.html)
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Torchred96
11-28-2015, 03:00 PM
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
11-28-2015, 03:55 PM
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
11-28-2015, 05:45 PM
Thanks Jerry .I appreciate the feedback.