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

Shu

iTrader: (2)

ls1howto.com will set you straight.

2edybrd

Thanks, That's the sight that said to torque the replacement to 37 foot pounds

smask04C5

iTrader: (1)

It actually states to torque new balancer bolt to 37 ft#'s plus 90*. Aftermarket ARP bolt is torqued to 190 ft#'s. Hope this helps.

Bluehawk27

its actually 37 ft/lbs + 140 degrees for the OEM bolt

LS1_PNYTAMR

iTrader: (1)

240 is what ur supposed to do yes... how hte hell you got it that high i dunno. best i could get mine was about 200

blkZ28spt

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.

2edybrd

200 is about as good as we got as well. Well, that's fine then. Now all I need is a good tune.

pekkaz

After seating the pulley I just torque the new bolt as hard as I can using ~2ft bar and don't even look at degrees or torque. I've found out I can pull max 110 degrees after the initial torque.

GuitsBoy

iTrader: (4)

37 ft lbs plus 90 degrees is what jMX says is "good enough". Actual spec is 37 ft. lbs. plus 140 degrees, as stated above.

777

iTrader: (21)

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.

robertbartsch

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...

777

iTrader: (21)

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.

Loudmouth LS1

iTrader: (10)

That's the spec I was lookin for, but I have a question, is it ok to just impact it? My buddy's always impact the stock bolt and have had no problems of it backing out. The only problems i've heard of the stock bolts backing out is when people torque them, so is it ok to impact the ARP bolt also, cuz I bought an ARP one?

robertbartsch

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....

blkZ28spt

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.

robertbartsch

How about those pricey head bolts..... they could fund all their pension plans with the extra dough from these pups...

ArKay99

iTrader: (1)

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.

white01ss

iTrader: (37)

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.

Tally TransAm

iTrader: (17)

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