Overtorqued crank bolt
Thread Starter
Launching!
Joined: Aug 2002
Posts: 264
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From: Milwaukee
Overtorqued crank bolt Hey everyone. My friend and I put a cam into my GTO the other day and he happened to remark to me that we had to torque the bolt to 200 - 240 foot pounds.
This seemed a little excessive to me, but he says that the research he did showed the final torque specs to be at 240 foot pounds.
Now I did a search here and on a couple of other sights, and I get conflicting reports. One sight said to set the bolt at 240 Foot pounds and then retorque the replacement to 37 foot pounds, while another sight said that 240 foot pounds is the final torque spec.
Can you guy help me out here. Which torque spec is correct?
I have two extra bolts and plenty of time, so changing the crank bolt out isn't going to be a problem. But I would rather not have pull the radiator back if I don't have to.
Thanks
John
This seemed a little excessive to me, but he says that the research he did showed the final torque specs to be at 240 foot pounds.
Now I did a search here and on a couple of other sights, and I get conflicting reports. One sight said to set the bolt at 240 Foot pounds and then retorque the replacement to 37 foot pounds, while another sight said that 240 foot pounds is the final torque spec.
Can you guy help me out here. Which torque spec is correct?
I have two extra bolts and plenty of time, so changing the crank bolt out isn't going to be a problem. But I would rather not have pull the radiator back if I don't have to.
Thanks
John
Originally Posted by 2edybrd
Hey everyone. My friend and I put a cam into my GTO the other day and he happened to remark to me that we had to torque the bolt to 200 - 240 foot pounds.
This seemed a little excessive to me, but he says that the research he did showed the final torque specs to be at 240 foot pounds.
Now I did a search here and on a couple of other sights, and I get conflicting reports. One sight said to set the bolt at 240 Foot pounds and then retorque the replacement to 37 foot pounds, while another sight said that 240 foot pounds is the final torque spec.
Can you guy help me out here. Which torque spec is correct?
I have two extra bolts and plenty of time, so changing the crank bolt out isn't going to be a problem. But I would rather not have pull the radiator back if I don't have to.
Thanks
John
This seemed a little excessive to me, but he says that the research he did showed the final torque specs to be at 240 foot pounds.
Now I did a search here and on a couple of other sights, and I get conflicting reports. One sight said to set the bolt at 240 Foot pounds and then retorque the replacement to 37 foot pounds, while another sight said that 240 foot pounds is the final torque spec.
Can you guy help me out here. Which torque spec is correct?
I have two extra bolts and plenty of time, so changing the crank bolt out isn't going to be a problem. But I would rather not have pull the radiator back if I don't have to.
Thanks
John
11 Second Club
Joined: Feb 2003
Posts: 5,524
Likes: 1
From: The South
You are supposed to stretch it into place. I believe the 37 lb feet + ~90* is right. (I remember thinking 110*)
I got mine to the max on my torque wrench (250 lb feet) and I don't think it had stretched quite far enough to meet spec, but I called it good.
Edit:
https://ls1tech.com/forums/showpost....9&postcount=49
Crankshaft balancer bolt (new), 140* final pass.
I got mine to the max on my torque wrench (250 lb feet) and I don't think it had stretched quite far enough to meet spec, but I called it good.
Edit:
https://ls1tech.com/forums/showpost....9&postcount=49
Crankshaft balancer bolt (new), 140* final pass.
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I'll tell ya what you do. You pull the crank with the old bolt and tighten it as tight as you can with a 18" breaker bar. Then take it back off and do the same with the new bolt but leave it on. I see no point in even needing a toque wrench when no one can get it torqued to spec anyhow. They basically just tighten it until they cannot tighten anymore.
TECH Veteran
Joined: Aug 2002
Posts: 4,055
Likes: 1
From: Hartsdale, NY
I put one crank bolt on too loose. It casued a mouse-like noise in the pulley system that drove me crazy (no pun).
So I got a huge lead pipe and 36 inch breaker bar and cranked that baby down extra tight - now the mouse is dead...
I suspect using the old bolt will work just fine but lets not re-hash the torque-to-yield bull **** again! Apparently, the engineers who designed this horse **** really brain-washed the public and casued GM to generate extra parts revenue.
These guys should get big stock option payments and cash bonuses for their good work...
So I got a huge lead pipe and 36 inch breaker bar and cranked that baby down extra tight - now the mouse is dead...
I suspect using the old bolt will work just fine but lets not re-hash the torque-to-yield bull **** again! Apparently, the engineers who designed this horse **** really brain-washed the public and casued GM to generate extra parts revenue.
These guys should get big stock option payments and cash bonuses for their good work...
I'm sure it's 
you need new gaskets when you change heads and stuff too huh. Sure it's fine, until you see it leak. Sure using the crank bolt is fine until you see it break. 
I'd rather spend $5 and be safe than sorry.
you need new gaskets when you change heads and stuff too huh. Sure it's fine, until you see it leak. Sure using the crank bolt is fine until you see it break. I'd rather spend $5 and be safe than sorry. 
Originally Posted by smask04C5
Aftermarket ARP bolt is torqued to 190 ft#'s.
TECH Veteran
Joined: Aug 2002
Posts: 4,055
Likes: 1
From: Hartsdale, NY
Actually, I asked this question of a licensed engineer who studies metal in various design applications. He said the torque-to-yield idea is an interesting theory but is primarily designed to sell more factory bolts....
He concluded there is nothing special about TTY bolts; they are constructed just like the old-style bolts that people have been re-using for decades. The TTY system of tightening bolts is somewhat more accurate than just torqing in sequence to a specified reading. Apparently, that is the only advantage.
Yeh, according to him, you can use a TTY tightening method with used bolts and obtain a similar clamping result compared with new bolts.
I thought lots of shops now re-use crank bolts but I could be wrong...
So I used new bolts during the last build up but I still feel like a dope after I found out my Chevy dealer has re-used TTY bolts for years with no hicups....
He concluded there is nothing special about TTY bolts; they are constructed just like the old-style bolts that people have been re-using for decades. The TTY system of tightening bolts is somewhat more accurate than just torqing in sequence to a specified reading. Apparently, that is the only advantage.
Yeh, according to him, you can use a TTY tightening method with used bolts and obtain a similar clamping result compared with new bolts.
I thought lots of shops now re-use crank bolts but I could be wrong...
So I used new bolts during the last build up but I still feel like a dope after I found out my Chevy dealer has re-used TTY bolts for years with no hicups....
11 Second Club
Joined: Feb 2003
Posts: 5,524
Likes: 1
From: The South
Do not use an impact to install the crank bolt. That's what the majority will tell you, and I'm inclinded to believe them.
I'm sure GM makes a lot of money off of selling ~$5 crank bolts to us enthusiasts.
I'm sure GM makes a lot of money off of selling ~$5 crank bolts to us enthusiasts. 
The correct way as explained on LS1HowTo.com is to get the pulley on. Then use the old bolt to tighten it on and go to 240 ft/lbs. with that bolt. Then remove that bolt and install the new one and tighten to 37 ft/lbs. Then tighten anothe 140 degrees. Then have a few 
because you will be sweating. I used a big *** torque wrench (250 ft/lbs), and a 30" breaker bar I bought in Pathmark for $9.99, yup Pathmark, and I weigh 205lbs stand 6'tall and had all the veins in my neck sticking out. But I did it and it's on there good. That was the first time. The second time I put it on I did the above and before I put the new bolt in I pinned the crank.
because you will be sweating. I used a big *** torque wrench (250 ft/lbs), and a 30" breaker bar I bought in Pathmark for $9.99, yup Pathmark, and I weigh 205lbs stand 6'tall and had all the veins in my neck sticking out. But I did it and it's on there good. That was the first time. The second time I put it on I did the above and before I put the new bolt in I pinned the crank. 
Use a pulley holder... I just put mine on last weekend and muscles are still sore as heck. And no wonder... tighten to 240... loosen... tighten again to 120-140 degrees. Ouch!
The ARP instructions said 120 degrees which is about all I could do and I'm not a small guy either. The first 90 degrees I could do my hands, but the last 30 degrees I had to grab hold of the sway bar and push on the 1/2" breaker bar with my foot. It flexed so much I thought it would break. Time for a good breaker bar. Thanks to code4's pulley holder that made so much easier.
The ARP instructions said 120 degrees which is about all I could do and I'm not a small guy either. The first 90 degrees I could do my hands, but the last 30 degrees I had to grab hold of the sway bar and push on the 1/2" breaker bar with my foot. It flexed so much I thought it would break. Time for a good breaker bar. Thanks to code4's pulley holder that made so much easier.
i weigh 125 lbs and can get it to 140 degrees with ease.
the trick is beer and jumping jacks, plus an 18" breaker bar with a 4 foot jack handle slipped over it, hehe
use the biggest pipe you can find, leverage is your friend
the trick is beer and jumping jacks, plus an 18" breaker bar with a 4 foot jack handle slipped over it, hehe
use the biggest pipe you can find, leverage is your friend