Why won't this crank balancer bolt stay tight?

Posted By: ProSport

Why won't this crank balancer bolt stay tight? - 09/24/10 11:59 PM

This is an ARP bolt, I tightened it slowly with my fingers on the washer and it tightens up against the washer nicely before the bolt starts to get real tight, so it's not bottoming out and I don't need a thicker washer. After 2 passes down the 1/4 mile this thing comes loose, even after I thread locked it and torqued it.
I did notice that the crank snout is not flush with the harmonic balancer so the bolt/washer is tightening up against the balancer. I don't know if the balancer will go on any further, and my alternator belt is still lined up perfectly.

Posted By: Dart Racer

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 12:03 AM

Are you using a torque wrench to tighten or just "guessing" as you tighten by hand?

Mine came loose a couple of times until I used the torque wrench and proper torque on it.

Posted By: racerhog

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 12:11 AM

Sounds like the damper is not on all the way. Or your not getting it torqued rite...

Posted By: ProSport

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 12:36 AM

Yes, using a torque wrench. I even tried putting a long bar on the end of my 1/2" drive ratchet and tightened the crap out of it. I'm gonna try to get the balancer on further tonite.

Posted By: moper

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 12:38 AM

It should seat on the balancer. How was the engine balanced? Harmonis wil loosen them too... Check your convertor bolts.

Posted By: dOc …

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 12:43 AM

Quote:

It should seat on the balancer. How was the engine balanced? Harmonis wil loosen them too... Check your convertor bolts.

x 2

Posted By: sixpackgut

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 12:47 AM

i was thinking about buying that bolt, then thought to myself, how tight would an ARP ballancer bolt need to be to stretch it so it wont vibrate out. i didnt buy it

Posted By: dOc …

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 12:54 AM

Just a quick Q .... how much deeper will the bolt go into the crank ... without using the washer ?

Posted By: Chris'sBarracuda

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 12:59 AM

Quote:

Quote:

It should seat on the balancer. How was the engine balanced? Harmonis wil loosen them too... Check your convertor bolts.

x 2

x3..

If the engine is out of balance it will vibrate out..

Been there done that..

Chris..

Posted By: 602heavy

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 01:08 AM

Had this same issue , track marshall came to see me twice in the pits when i left the damper bolt on the track (twice

)......the bolt was torqued 120ft lbs with the balancer real tight on crank snout , the damper was around 1/4" short of bottoming out on crank for correct belt alignment , in the end i had to bite the bullet & put a spacer between damper & crank , no more problems , was using the same ARP bolt in pic.

Posted By: DoubleD

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 01:14 AM

What dampner are you running - I will bet you need the long bolt!

Posted By: Cab_Burge

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 02:03 AM

Some of the Mopar factory service manuals call for 120 Ft LBs torque and others call for 150 lbs, what are you torquing yours to? As already siad, try removing the washer and see if you can screw the bolt in pass the outer edge of the balancer, if you can it is not bottoming out. the bolt is suppose to be tighten up against the balancer, not tighten up by bottoming out

You can also look at the first one or two threads on the end of the bolt that srews into the crankshaft, if there laid over and damaged it may be bottoming out

if there good it isn't usually. Let us know what you have to do to fixed it, I had one (Hemi four speed car, race only, let the clutch out at 6000 + RPM and shifted it at 7000 RPM

) that wouldn't stay tight until I torqued to 150 lbs with blue loktite

Posted By: Butch

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 02:04 AM

Have you checked to make sure the bolt isn't bottoming out?

Posted By: ProSport

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 05:45 AM

I'll check the bolt length tomorrow(bottoming out), the damper is a TCI Rattler. I was torqueing to 120 but also tried much higher with a long bar as I mentioned earlier.

Posted By: MR_P_BODY

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 12:50 PM

Quote:

I'll check the bolt length tomorrow(bottoming out), the damper is a TCI Rattler. I was torqueing to 120 but also tried much higher with a long bar as I mentioned earlier.

I always use a impact to pull the damper on... I make
sure the bolt is near 3/8" to 1/2" from being bottomed out
and stack up washers to pull it on... that way I have
plenty of threads holding... the shock from the impact
really helps move the damper over a steady pressure

Posted By: rebel

Re: Why won't this crank balancer bolt stay tight? - 09/25/10 01:49 PM

pull the damper & check the crank snout now before you run the engine again. if it's got fretting on the snout you have a harmonics problem & it's good to catch it early. leave it too long & you've got a machining bill to add to your problem. ask me how i know?

Posted By: ProSport

Re: Why won't this crank balancer bolt stay tight? - 09/26/10 06:46 PM

Everything looks clean and normal, and the bolt is NOT bottoming out. But this ARP bolt is 5/8" shorter than the factory bolt, so I'm gonna torque the factory bolt in there with thread lock and see how it goes.

Posted By: Joshs68

Re: Why won't this crank balancer bolt stay tight? - 09/26/10 07:01 PM

I have an ARP bolt (12 point)with the same TCI balancer that you do. I used the long bolt. mine has remained tight