99WhiteSS

I just realized that I reused my crank bolt when I reinstalled my crank pulley after engine rebuild. The engine only has about 6K miles on it now but I have noticed that it feels a little off balance and have been trying to track down the cause. I was thinking maybe the pulley/balancer was the problem and was planning on having the pulley reseated/installed. Should I go ahead and buy a new crank bolt (from GM, I guess?) or can I go on with the same one?

-Kris

The Juggernaut

iTrader: (7)

ALWAYS buy a new one.They're designed to strech.

Doug Tschantz

That pulley bolt is made of alum., which stretches when torqued. I would get a new bolt and see if that cures the problem.


Doug
00 Pontiac

Plum Crazy Rob

iTrader: (3)

The bolt is cad-plated steel, and doesn't have
the narrowed shank of a torque-to-yield design (look at a head bolt).

I've been a little curious if they don't have you
replace this because of the SEALER under the head
and it looks like it has factory loc-tite on the
threads.

Feel free to flame me on this! I can take the heat
<img src="images/icons/wink.gif" border="0"> It's a cheap enough bolt, so just replace it anyway. LOL <img src="images/icons/smile.gif" border="0">

CamaroCain

iTrader: (1)

We went a head and got the $3 bolt for our pulley we just ordered. I think GM requires it to be changed.

TA_2001

Use a new one..
All the cam install docs call for a new one.
The hotcam kit comes with a new one..

Terry

Raughammer

Can you? yes. Should you? No, not if you plan ahead and can afford 3 bucks.

But yes, I have helped folks who had no new bolt and they suffered ZERO ill effects. Though your experiance may vary.

New bolt? install it with NO added loktite.
Used bolt? add a dab of RED Loktite.

CamaroCain

iTrader: (1)

talking about it being a torque to yeild bolt:
"The bolt is cad-plated steel, and doesn't have
the narrowed shank of a torque-to-yield design (look at a head bolt)."

Not to sure how much it helps, but the torque spec from GM on a new crank pulley belt is:

37ft-lbs--first pass
140 degrees--second pass

just me

I tend to agree with Plum Crazy Rob.
The bolt has no undercut and is to short for it's diameter to be a TTY.
Just because a bolt is tightened using an angle sequence does not mean it is a TTY bolt.
If you really want to check you could measure a new and old bolt.
But they are so cheap that I see no reason not to replace them with new ones each time.

Plum Crazy Rob

iTrader: (3)

And I agree 100% with everything Just_Me just
said <img src="images/icons/grin.gif" border="0">

If it was a $20 bolt....well maybe...but for $3
replace it. Being ghetto is noble, but there comes
a point where it doesn't pay <img src="images/icons/smile.gif" border="0">

Colonel

I've re-used them a few times without problems....

...and then a Bowling Green I had the bolt back out on me! The crank pulley almost fell off! <img src="images/icons/shocked.gif" border="0"> Yes, it was most certainly tight before hand. It was either that it had been used one too many times or some ******* loosened it.

From now on I'll be using a new one each time the crank pulley is off.

just me

I am pretty sure the reason these bolts come loose is the damper is moving on the crank because of no key.
If the damper rotates at all then you lose the seat of the bolt/damper/camgear to crank relationship and the bolt is going to lose it's torque and then it can back out.
I never had a problem with it coming loose until the blower.
I cut my crank for a keyway and that had better cure the problem.

Matt98SS

first time I ever did it I went to my local dealer and asked for one and they are like what the hell do you want this for. I told them and they said we just reuse em with loctite on them that is all you have to do.

as others said its 3 bucks so I got it anyways but I have reused it before no big deal

Larry

iTrader: (4)

I have had my pulley off twice and used the same bolt both times. I use plenty of 242 Loctite and haven't had a problem. As much interference as the pulley had with the crank I don't think it will turn when impacted and Loctite used.

just me

Larry, it can and often does spin when you start loading it hard with a blower as many of us have found out.

Terry Burger

iTrader: (4)

I reuse them a lot, never had a problem.

Pro Stock John

iTrader: (34)

Sure it happens to 93-97 LT1 cars too until they keyway the crank snout.

just me

The lt1's don't have a keyed crank either?
well my ls1 is now keyed.
I always use plenty of red loctite and I had reused a stock bolt 3 times NA with no problems.
With the blower it was a new bolt loctited and torqued perfectly.
After about 3 weeks after moving to a smaller blower pulley for more boost, it then loosened up.
I retightened it and it was marked to check for movement.
It did not spin after it was retorqued and I thought all was well.
When I recently tore down the motor and when I pulled the damper I found 2 360 degree grooves in the snout and when the damper was removed the material from those grooves also scored up the crank as it was pulled off.
Luckily it's not all that bad and it still fits extremely tight.
But now it is also keyed so the bolt can't lose torque by the damper spinning.
ATI makes some sort of dowel pinning kit now for blown and circle track use...from thier website-
LS1 Crank Pin Drill Fixture Kit
The ATI Crank Pin Drill Fixture Kit for the LS1 Super Damper allows you to install 1 or 2 dowel pins to the LS1 crank, eliminating the damper twist on the shaft. This is a must for circle track or super charged engines.

Application Part No. RN Price
LS1 Crank Pin Drill Fixture Kit 918993 $121.93

I don't know how that works though.

Plum Crazy Rob

iTrader: (3)

LT1s have the keyway cut in the crank, but nothing in it with the stock crank hub. You buy a keyed hub and then stick the woodruff key in - had to do this myself !!! LOL <img src="images/icons/smile.gif" border="0">

Larry

iTrader: (4)

just me (Steve),

I don't feel that a harmonic balancer type pulley should ever pull a blower. Not only can the pulley turn on the shaft or its molded rubber but it can be positioned or pushed out of balance if the belt is over tightened. And some blowers do have mechanical tensioners that can be over tightened.

The blower should have another pulley installed inside the harmonic balancer and bolted to the center portion of the balancer. Of course this requires enough clearance to accomplish this type design.

The blower will be limited to amount of boost and/or rpm if driven by the harmonic balancer.