On my new motor (in sig), the crank bolt keeps coming loose. One time to balancer actually flew off. Put locktite on it, and tightened it, and it was still loose after running the car (at idle) for about 10 minutes. Any ideas?

 

My only guess is that the hub isnt fully seated. Ive had to tightten it, then take and tap the socket (5/8" deep) with a hammer, then tighten it some more, tap, tighten and so forth. More of a problem for me caus' the blower pulley.

 

On top of the tighten/tap method you might try buying a new hub bolt. Your threads might be worn or stretched.

 

Is the hub a tight interference fit with the crank snout? Are you using the correct bolt with the large hardened washer? Are you tightening it to 74 LB-FT? Is the CKP reluctor installed behind the hub?

1993-1997 crank hub bolt - 9440024

1993-1997 crank hub bolt washer - 10128306

 

Same thing happend to me with my car, I ended up just buying a new hub from Thunder Racing along with a new bolt and voila(sp?) problem solved. I noticed that the old one just came on/off with no trouble and maybe that caused the bolt to back out with vibrations or something. After all the trouble I had Im glad its fixed. Good Luck!

 

Lloyd,

This is Jake at Cook Performance Engines.
Did you ever get the crank bolt problem fixed? Did you try the ARP bolt like I suggested?
Give me a call if you need any more advise.
Once again, thanks for the engine purchase!

www.cpengines.com
765-352-3626

 

Tried the ARP bolt and it's working great. This is his son Chris though

 

Does the ARP bolt still use the crank hub washer? I noticed it comes with a washer itself.

 

The washer that the ARP bolt comes with is meant for some kind of aftermarket balancer, I even had to turn down the head of the bolt a bit to get it to work on my stock hub. You have to use the stock washer if you're using the stock hub.

 

I went ahead and ran the arp bolt with the stock washer and hub and it fit perfectly. I went to 90ft/lbs according to ARP w/o moly lube. I swear I'm gonna check that thing once a week for like a month because I'm not losing another hub/pulley and ****ing $25 bolt! Haha. On a side note I created a really easy to use hub puller for $15 using an existing kit and ofcourse modifiying it since most don't work with the Lt1.