Question on reusing rod bolts

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363
Location
Va
Im going to pull the pan on a 4200 Vortec to check for a possible rod knock. This noise just started within the last month so I stopped driving it. I'm not going to remove the mains since I cannot remove just one cap, it's one ladder-style brace and those bolts are TTY. My question is, the rod bolts are 18 ft lbs plus 110 deg, can these bolts be reused for the sole purpose of checking clearance with plastigage? Will get new bolts for the new bearings if the crank is ok. I'm going to get a mic on the journals as well but would like to use the plastigage also.
 
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9,035
Location
Houston, TX
It would likely depend on whether or not the bolts are TTY as well and if they are part of the reason for the rod knock (i.e. they have stretched). In my experience with various engines, if you replace the rod bolts, you have to have to rods resized. I know this does not directly answer your question, but hopefully, it provides some food for thought.
 
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25,805
Location
MA, Mittelfranken.de
They can usually be used a couple of times so for your measuring purposes it should be fine. Use only OE bolts or you may have problems and need to resize the rods as the other poster said, aftermarket bolts like ARP may have a greater clamping force and may distort the rod cap.
 

i6pwr

Thread starter
Messages
363
Location
Va
Ok, thank you. Yes, will use OE bolts, I wish the rods used regular bolts with nuts but this seems to be the trend. As long as I can get a reading on the plastigage with the old bolts I'm fine. The new bolts I only want to use once. Good point also on the bolts stretching...not sure if that's what's going on here but good info, will surely look at everything.
 

i6pwr

Thread starter
Messages
363
Location
Va
Originally Posted by Snagglefoot
If you find the culprit bearing, show us a pic. smile
Will do.
 

i6pwr

Thread starter
Messages
363
Location
Va
Originally Posted by atikovi
Originally Posted by i6pwr
I'm going to get a mic on the journals
Is there room to check in 2 or 3 places? In case it's oval.
I believe there is. Being an inline-6 I want to say I can get at least 2 readings,
 
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