ATI spun off my keyed crank hub..help!

**SSmaro** · 05-28-2007, 08:37 PM

Okay, here's what I have(or had) on my car:
D1SC 7.65 LT1 balancer
Keyed Professional products SFI Damper
Keyed crank hub/crank w/woodriff key installed.
3.4 pulley-making 11# boost on my car

Here's what happaned:
I dyno tuned my car and beat the crap out of it-no problems
Then, at the track, I blip the throttle to clean out the plugs and then my damn shit puled right off-crank bolt, balancer, ATI spacer/crank pulley, belts etc.

I don't understand how this happened as my ARP crank bolt pulled out, threads were good, but it was bent.
My balancer was split at the spot where it is keyed all the way through.
The key was in good condition.
The spacer/ATI crank pulley was still in tact as one peice like it is installed.
The crank is not bent, threads are still good.

I think the keyway on the damper split under the pressure, then it was spun off the crank-backing out the bolt, and then bending the bolt as it came off. The bolt did not break.

Anybody with a LT1 and some moderate boost have some advice? I used loctite everywhere, yet this still happened. What should I do next time??? I just lost 1,000 in parts and dont want this to happen again. please help or offer your .02!!! Thanks!!
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**LS2Tuner** · 05-29-2007, 03:34 PM

Anything we build that will spin 10lbs or more of boost we send the crank and balancer out to a different specialized machine shop to cut another key way 180* off from the stock one for added strength just so what happened to you doesn't happen.
There are MANY possiable reason. The balancers hub could of had a bad heat treating to where it wasn't hardened like it ahould of been.... The key way could of statred to roll which split the balancer because the keyway was tool steel strength and the hub wasn't.....ect.
Either way you NEED to replace ALL parteven if they look ok.
When you intall the new balancer install with installing tool NOT pulling it down with the bolt!
Locktite only takes a drop or two!! Too much makes it worse than none at all there rep told us before.
Torque bolt with a modern torque wrench that has been calibrated and not trown around and left with the handle cranked up to 75 lbs for an extended period.
Change your oil cause it was VERY hard on your bearings when this happened.
Thats my 2 cents.

**LS2Tuner** · 05-29-2007, 03:36 PM

O'h yeah don't buy another Professional Products Jap junk balancer!!

**SSmaro** · 05-29-2007, 03:56 PM

Originally Posted by LS2Tuner

O'h yeah don't buy another Professional Products Jap junk balancer!!

Thanks for the advice. I need to make sure this does not happen again. What hub/balancer combo do you recommend? Also, at this point taking my crank out is not really an option, so do you think I can recover with it still in the car?? Thx!

**LS2Tuner** · 05-29-2007, 09:44 PM

We have used the TCI Rattlers and NEVER had any problems. If your on a budget I would get one from Pioneer. Make sure it's a SFI and a race style that is made for extreme stress and abuse. ATI makes a nice one too as long as it's NOT their "street" one.
Yeah my friends own a major speed shop I'm VERY familiar with Profession Products balancers. He will NO longer even let customers special order there balancers.