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Discussion Starter · #1 ·
Guys I am new to ls stuff period. A friend has an LS2 that he thought had a small rod knock. They put it on the lift, pulled the pan and tried to see if there was any slop in the rods. There were a couple that were questionable, I felt a little movement. So we pulled the cap off the questionable rod and saw some wear in the bearing, but not too much. He wants to go ahead and replace all the rod bearings just to be safe. I have read on multiple forums and some say you cannot reuse the bolts and some say you can. Some say they are TTY and some say they aren't.

I just need guidance as to what to do to put these rod bearings in?? Do I reuse the factory bolts or not? Do you torque them to 15 ft lbs and then turn 75° more??

Please advise ASAP as he wants to try to reassemble this afternoon, otherwise, it may have to sit for a while.

Thanks
James
 

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Yeah they're reusable. If I'm not mistaken, GM put out a TSB to increase the angle from 75 to 85 degrees, so even if they were TTY, they probably didn't go into yield.
 

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The only bolts in a LS motor that are not reusable are the 11mm head bolts and the crank bolt. Everything else is good to go.
 

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Some of the bolts are actually Torque to angle not Torque to yield.
This is correct. Torque turn is simply a method of fastener torquing that takes bad technique and incorrectly calibrated torque wrenches out of the equation. We use a modified torque turn method when torquing aftermarket head studs, even. Torque to yield means that you've stretched the fastener beyond the point that it's able to return to its original length when the load is removed from it. These fasteners are typically made of a softer alloy, and are designed to stretch more from the get go. I can get on GM globalconnect and show you a screenshot of the actual service procedure if you have doubts.
 

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Discussion Starter · #7 · (Edited)
Well, we pulled it apart last night and #6 rod bearing was worn and galled pretty bad. It appeared to be ready to spin had we not caught it. The guy whose car it is got an LS book and I read through it, along with the info online and here on the bullet, I found out it was torque to angle. Go to 15 pounds and then 75 for early design and 85 for later design. One thing I did for piece of mind was use an old dial torque wrench to break one loose to get a torque reading. I then checked the torque on one after the torque to angle and they were within 1 pound. Made me feel better about it. We did have to clean up the crank journal a little but it was not hurt since it was shutdown right away upon the noise.

My question and future concern is, why would this happen?? He was not manually shifting the auto trans or anything, so I do not think it was over revved or nothing like that. Any thoughts??

thanks
James
 

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Discussion Starter · #9 ·
It is actually a 56 t-bird kit car. The engine is said to be a 6.0L LS2 out of a 2007 corvette but I have not confirmed that. That is what he ordered rod bearings for and we put in it. He has now started it and drove it. Said it had a little knock on initial start up but went away and seems fine now other than he ahs a misfire in one cylinder now. Not sure what is going on. He was going to un hook the battery last night and hook it back up this morning thinking maybe the computer needed to be reset after the knock sensor did its thing?? I don't know. Like I said, first LS I have ever been into.
 

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Discussion Starter · #11 ·
"Hard as a preachers pecker", I have never heard that before. That is funny. I am going to use that in the future.

As for the rod, he wanted to try to get it together for this weekend. It may be re addressed later on, so it may have to come completely apart. Can you resize them since they are powder metal?? I didn't think you could mill down the mating face. Would you go oversize and get a larger "OD" bearing?? I have heard of going smaller "ID" when you turn the crank, just didn't know if this was an option.

Thanks
James
 

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"Hard as a preachers pecker", I have never heard that before. That is funny. I am going to use that in the future.

As for the rod, he wanted to try to get it together for this weekend. It may be re addressed later on, so it may have to come completely apart. Can you resize them since they are powder metal?? I didn't think you could mill down the mating face. Would you go oversize and get a larger "OD" bearing?? I have heard of going smaller "ID" when you turn the crank, just didn't know if this was an option.

Thanks
James
You don't have to cut the parting surfaces on these rods, just hone the ID out by about .002" and use a bearing, like a Clevite 1776p, for the larger ID.
 
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