well its happended three times and i have no idea why. i torque it down to the right specs and even coat it with red loctite. they still end up backing out and my hub coming loose.

first one lasted around a year, the next a few months, the next a few days.

i have no idea what im doin wrong.


car info:
its an internally balanced 383
A4
4:10's
stock stall
underdrive pullies
full exhaust
full msd
and other bolt ons


any help would be appreciated!

 

Stock balancer? Neutrally balanced flexplate?

 

Are you reusing the stock bolt each time?

I would buy a good quality ARP bolt and see if that helps. What are you torquing it to?

 

Sounds like something is either out of balance or those threads are beat up pretty bad.
That bolt should not be wiggling free with 70lbs and red on it.

When it's first installed, does the motor feel like it's shaking?

 

yes the flywheel is nuturaly balanced, and has stock front damper

im not reusing the stock bolt cause they fall out after coming loose, im just using a grade 8 bolt of the same specs. im torquing to 74 lb

the motor doesnt seem to be shaking like something is unbalanced, thats why im confused about it.

 

Is the bolt you are using of the same length? Is the hub fully seated?

Perhaps the threads are chewed up enough where it's no longer clamping.

 

well i figured it out... finally lol.

you know how the hub is keyed to fit on the crank in the slot. well the part inside the hub is gone and has been broken off. which would make the hub want to spin and its weight spining against the bolt would work it loose.


.....anyone have a spare hub laying around i could buy?

 

Last I checked the LT1 crank is NOT keyed.

 

Are you also using the extra-thick plate washer and a lock washer?

Are you sure the bolts you've used are the correct length?

I'm now wondering if he OD of the crank snout is a tad too small. The hub's a press fit and should have taken an installer tool to put on.

Is your aftermarket crank cut for a hub key? If it is you can have your hub broached for the Woodruff key. Golen Engines, and probably other, will do it for around $80.

Jake

West Point ROCKS!

 

It may be the same thing that happened to me. The bolt started backing out so the hub became loose and crank actually damaged the inside of the hub and now it will not seat correctly and stay tight. I ordered a keyed hub from jegs. I haven't had a problem since. Examine the inside of the hub and you will probably see it is damaged. The hub costs about 70-80 dollars from Jegs.

 

yea i realized right after i posted that, when i was looking up hubs that the factory one is not keyed. yes i can see a little damage on the inside, thats why i thought the keyed section was broke out of it.

just got confused since my crank is slotted for a keyed hub.

hmm.... i guess my only real option is to just buy a keyed hub.

so the hubs from jegs or thunder racing would fit my eagle crank?

and also, do they come with the key?

 

You can get a key from any parts store. I can vouch for the piece from Jegs. Really nice!!!

 

Consider yourself lucky. I had my bolt come out a few weeks ago only to find out it damage the crank snout. Talk about a nightmare.