Crank bolt backed out how to prevent it again
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Teching In
Joined: Jan 2023
Posts: 3
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Crank bolt backed out how to prevent it again Hello I have a ls1 cam/intake with a 3600 stall converter C5 Corvette During installation of my rebuilt auto trans I was installing the torque converter bolts and went to the crankshaft bolt to turn the crank to bolt up a torque converter I noticed that my harmonic balancer bolt backed out almost it was super lose this must’ve been recently right before the transmission broke due to me driving a car for almost 1month daily The harmonic balancer never backed out it is still in the same place from when I installed it and have had no oil leaks from the crank seal but during my installation process I used an ARP bolt at first wich striped inside of the crank due to me being an idiot trying to use it to put on the harmonic balancer but then cleaned out the crank with a chaser and was able to install a NEW OEM bolt I followed the procedure from gm and everything used a harmonic balancer install tool as well to prevent the strip again worked fine until I luckily noticed it backed out could this be due to damaged crank threads or should i go to an arp bolt I was able to remove the bolt easily do to my Motor being tilted because I’m installing my transmission i was abel to remove the bolt at that moment the bolt looked perfectly fine there were no crank threads in it nore was the bolt damaged it looks like it just walked its self out could this be the balancer i got from summit walking it out or could the shitty harbor freight torque wrench i used be at fault i am installing a arp bolt this next weekend and would just like some advice to prevent this from happening again thank you
install the arp bolt with the arp lube on the threads and both sides of the washer, tq to 235 ft/lbs and be done. As long as the balancers installed correctly you shouldnt have any issue.
Joined: Apr 2006
Posts: 3,894
Likes: 1,139
From: Grand Rapids, Michigan
There's no Harbor Freight torque wrench that goes up that high, as far as I know, so that could be part of the problem. Make sure you have a crankshaft holding tool in place when you torque it, otherwise you'll struggle to reach the torque value.
On The Tree
Joined: Jan 2023
Posts: 144
Likes: 54
Is there an updated or preferred torque spec for everything on an LS engine?
I've had this happen also.
The book says 111 Ft Lbs then back it off 360 degrees, then 59 Ft Lbs.
How is 59 Ft Lbs going to hold that on?
I've had this happen also.
The book says 111 Ft Lbs then back it off 360 degrees, then 59 Ft Lbs.
How is 59 Ft Lbs going to hold that on?
Joined: May 2004
Posts: 1,593
Likes: 267
From: Halfway back on the Highway to Hell...again!
If the bolt is loosening...IT'S NOT THE BOLT. The balancer is spinning on the crank, which in turn, loosens the bolt. I have seen this many many times. The only way to prevent this on a stock crank/balancer is you have to get the pinning kit.
https://www.summitracing.com/parts/i...MaArRdEALw_wcB
https://www.summitracing.com/parts/i...MaArRdEALw_wcB
