molson

Installing my ASP pulley,I used threaded rod to start the pulley on the crank

I then used the old bolt to fully seat the pulley and torqued it to 240 ft/lbs.

Then I removed the old bolt and installed my new G.M. bolt and torqued to 37 ft/lbs.

Heres the problem...you are supposed to rotate the bolt another 140 degrees.

I got mine to move about 45 degrees.

It will not move.

I checked the torque with my torque wrench and it is greater than 250 lbs( thats the highest my wrench goes)

What do you think I should do?

I am scared of breaking it.

Any ideas???

see5

I think you added the step where you torque the old bolt to 240.

I would quit and keep an eye on it.

minytrker

I would pull the bolt out and make sure its not crossed threaded but then you have to buy another bolt. I have dont 2 in the last few weeks and one went 140 real easy and the other went about 120-130 degree's.

molson

The bolt isn't cross threaded.

Put it in by hand,then torqued to 37 ft/lbs,which was less than 1 turn.

It then only went another 45 deg.

When I torqued to 240 with the old bolt it wasn't that difficult to do.

I have tried to turn it using ALOT more force and it won't budge.

Before installing I made sure it was the same length as the old one.

94legaleagle

I've NEVER used a torque angle gauge/meter, so if my input demonstrates my lack of knowledge, be forewarned!!

I believe some bolts, including the front damper pulley bolt are meant to be torqued to a certain foot pounds (here I'm guessing 37 foot pounds as you did), then you are supposed to torque them "x" number of degrees, then you torque them on the 3rd pass to the final foot pound specs.

I don't have a torque angle gauge and I've never used one, so I'm new to this concept - HOWEVER, I'm wondering, is there a difference in torquing a bolt to the 37 foot pounds, then simply estimating that you torqued it 240 degrees WITHOUT using a torque angle gauge, then doing the final torque?

I'm essentially wondering if there is a difference, for whatever reason, in the normal degrees we might tighten a bolt ie: quarter turn would be 90 degrees; 1/2 turn would be 180 degrees, 3/4 turn would be 270 degrees, etc) VERSUS the amount that a bolt is ACTUALLY turned, degree wise, IF A TORQUE ANGLE GAUGE IS USED? Put another way, is 180 degrees of a bolt turn by "guestimation" (assuming you closely estimate 180 degree turn) the SAME as 180 degrees of tightening as indicated by a Torque Angle Gauge?

If there is a difference, then I'd assume this is the problem. If there isn't any difference, then would someone please explain the purpose of a torque angle gauge? Why use one, and why not simply torque to the final end torque spec right away?

gamisou

The bolt is a torque to yeild bolt. It is tightened an initial amount In FT.LBs and then rotated a specified amount of deg. The bolts are designed to strectch a cretain amount during that, to acheive proper clamping force. That is why you should only use them one time, as they get stretched. You will have an extremely hard time breaking that bolt. If the manual says 37 FT.LBs do that with the tourque wrench, you can get a inexpensive angle gauge from a place like pep boys,or paint a white line on the bolt head or socket and tighten it another 140 deg. I would also recomend backing the pulley out some and using the new bolt to draw it on to the crank and use a breaker bar, you might as well throw your torque wrench away if you abuse it like that. You can always just slam the bolt on with an impact gun its the easy way out just use some loctite.

vettenuts

There is a measurement of crank snout end to pulley in the service manual. Did you check that after the tightening sequence with the old bolt? It might be that the bolt is bottomed in the crank if the pulley sits in farther on the snout. You are truly between a rock and a hard place. However, since the old bolt went in and out OK, you might be OK if you remove it. I am not sure what I would do at this point in your position. If you don't want to risk it, you could mark the bolt position relative to the pulley and keep an eye on it for a while to see if it moves. If it comes out, you will have to replace the bolt and likely the pulley as well.

Patches

The initial 240 lb. ft. spec is to push the pulley onto the crank snout a certain distance (see below) the 37 lb. ft. preps the new bolt for the torque-to-yield (TTY) step. TTY specs are more accurate than lb. ft. as they create a certain preload, stretching the bolt beyond the elastic range. This essentially locks the bolt into the treads. It is critical that you follow this procedure as specified. I have never had a new crank bolt back out or fail following the factory method.

Pinning the crank in two spots 180 degrees apart is the ultimate insurance and is what I recommend when you have the pulley in, right before installing the new bolt. Also, I recommend replacing the pulley each time it's removed as the press fit is largely lost when it's removed.

Prees-on distance spec from the manual


I make markings on the pulley and bolt head to indicate the 140 degrees that needs to be attained. It takes considerable force to turn it that far - I use a strong cheater pipe with a breaker bar.


Pinning tool


A pinned pulley - the dowel is used as the key

molson

I checked the balancer to crank snout spec. and it is fully seated.

I realize pinning is the only way to really be 100% sure it wont back itself off.

I kinda would like to know what turning the bolt 140 deg is equall to in ft/lbs.

any info on where to get a pinning kit and how much..$?

My original crank bolt was pretty loose when I started the tear down.

I wonder if the crank is not tapped all the way down in the hole and it is bottomed out.

If I don't pin it I will probobly get a new bolt and grind a 1/8 " off and try that.

Dan_the_C5_Man

Err, be careful with that statement.. We've seen plenty of broken bolts (even a few ARP's) in the crank recently, here and on LS1Tech, and it is a nightmare to deal with.

see5

Part of the 140 rotation is pulling the pully on. You pulled it on with the old bolt which is not part of the proceedure so it is no wonder that you can't do another 140.

mph1972

Nice post!

Let me tell you, I am a petty big guy and I must tell you getting that bolt torq to spec can take a lot. I am practically lifting the entire front in of my car off the jack stands and I am not making that up. I make the same marks and do everything I can to ensure that bolt is doing it's job and making sure it will not back out.

Not to offend you, but you may want to put a little more a$Z in it and ensure you get that bad boy on good!

Mike94ZLT1

Why don't C5's have 3 extra crank bolts like F-bodies do? My Camaro has the large one in the middle, and 3 other ones around the edge?

gonbad

You seat the pulley with the old bolt by torqueing it to 240ft lbs. You lock in the new bolt with the 140 degree torque to yield. I used the end of my jack handle over a breaker bar plus two 200+ lbs guys, one pulling and one pushing to get the full 140 degrees.

minytrker

The floor jack handle is your friend for this job.

molson

I had a 1/2 inch breaker bar and a length of pipe and it wouldn't budge.

The breaker bar was flexing quite alot....

I followed the procedure exactly,and have read every crank bolt thread I have seen in the last 18 months.

I just have to decide if I want to mess with it now or keep an eye on it for a while.

mph1972

Well, I would probably invest in a new bolt, take the one in there out and redo it. I am certain that you did things as they needed to be done, but if that thing backs out or other problems occur, you will wish you did it. The bolt only costs a few dollars and look at the bright side...at least you know your harmonic balancer is seated.

Good luck and sorry if I have came across as a jackaZ$, just trying to help.

Micah

Bill Curlee

TTT

BC

molson

It's not the price of the bolt....If I try to remove it and I strip the threads or break it off I am screwed!!

I was wondering if I could pin it with the bolt still in??

Drill through the bolt flange and into the crank/balancer and insert a roll pin??

BTW... I appreciate all the help and try not to read too much into peoples responses.

I am very reluctant to mess with it.

I am not sure what getting another bolt would do.What if the same thing happens??

molson

I used my electric impact and removed the bolt..

Not damaged @ all.