Schred86

Hey guys, I installed an ATI 10% UD this past winter on my mini build. Since then I probably put approx. 2k miles on it. Very quick car and awesome to drive.


So fast forward to this past Thursday. I take the car out and drive approx. 15 miles to see my uncle. We then go for a ride to show him what the z can do.


I do a 2nd to 3rd gear pull and then when deceling I hear a weird noise. I pull right over and shut the car down. Then I look near the belts since I smell burnt rubber and low and behold my pulley is on an angle rubbing against the steering rack. I also find a sheared off bolt on top of the steering rack. I am in absolute disbelief that this happened. Luckily nothing else was damaged.


I trailer the car back home and took it apart last night. Now the part that gets me is that I am super thorough when torqueing bolts and working on the z. These bolts were rechecked at least 3 times during the install. In addition, ATI puts locktite on the hardware.
The crank bolt is fine and secure. All 9 bolts are sheared off and are inside the hub. The inside piece separated from when the belts ride on. Later on today I will tackle removing the hub.


Now questions for you guys....
Have you ever seen this before?
Would you reuse the hub if the threads look ok?
Is it possible that the hardware failed?


I spoke to ATI and they want me to ship them the damper for them to look at it and see if could be a warrantied item.


I'm angry b/c I feel if I left the stock damper this never would have happened....but who wants to reinstall stock parts right?!?!


Any input is greatly appreciated. Here are some pics

Michael_D

Yes, there have been several reported failures just like what you have experienced. Do you know when you purchased this damper? ATI had a bad batch and you may be unlucky enough to have gotten one.

Millenium Z06

Are you sure you torqued them and blue locktited those bolts? It looks like they came loose and the elongated bolt holes.

I torqued those bolts to 16lbs and used blue locktite

Schred86

I purchased the damper in December 2016 from BTR. Definitely Loctite and torqued to spec.
What strikes me as a ood is if the outer pulley Spun on the hub, the bolt holes would not lineup. Which leads me to believe that the bolts just failed them selves

Millennium... i would re check those bolts just to be safe.

Whis9

Just happened to me, send them the whole unit, both pieces, mine was replaced under warranty.

When end I got new one back, I upgraded all hardware and lapped bolts in for almost 100% contact on taper.

I followed directions ions to the "t"
I also used an ISO calibrated torque wrench

16 ftlbs is not a lot
my hub actually look to have a lip on it, maybe hub not seating completely

I have all bolts paint marked and monitor them now

Schred86

Thanks for the input. Hopefully they do the same for me. I would definitely take the same precautions like you did next time.

Unreal

I believe AZdave had the same failure.

Dan_the_C5_Man

A trend is developing here.. Most definitely argue to have the unit replaced at no charge. You are lucky it didn't do more damage. And what a PIA to replace.

Schred86

Absolutely. I will be contacting them again tomorrow.

Michael_D

If it is a hardware issue (IE: the countersunk bolts), then ATI really needs to send out replacements to the rest of us who still have the chance to change them before the damn thing comes apart.

I had thought the most recent version was supposed to have addressed this problem. The most recent version is the damper that has the nine fasteners that the OP's has. His failure is pretty disappointing to hear......

Schred86

OK. I got the hub out. Looks like none of the bolts backed out. I will be sending this to ATI tomorrow.

Would you guys just reinstall the stock damper again or get another ATI and install it?

Unreal

Innovators west and be done. I would never put a stock one back on.

Schred86

I hear ya. I will look into innovators. Thx

BRING IT

Same thing happened to me a couple of months ago.

Mike44665

I went through the ATI "dilemma" where my damper fell on the crank, no installer tool needed, not the first reported here. Guy at ATI was doing his best to convince me that GM had a number of different size OD crank snouts, really.

A call to IW, discussed the crank snout sizes, there is only one. A little more money, but well worth the peace of mind, hey it's MY Vette. And besides it is a piece of art work, too bad it is so hard to see.

My $.02.

Schred86

Wow, im suprised to hear how many people are having issues.

Malfeitor

When you lapped the bolt tapers, did you notice abnormal contact after a couple of passes? Interested to know if you had high/low spots in the coutersinks. This seems like it would cause some slack or a weak spot under load and eventual failure. Good idea to lap IMO after seeing these fail. I thought it was odd when they used Torx Plus hardware on this setup. Didn't know they made T Plus hardware until I did this install. Had to order the tools.

Bottom two countersinks on the OPs pics looks abnormal. (compared to the rest, full contact.. )

Must_Have_Z

Ahh, famous last words. Here's my opinion: if it ain't broke don't fix it!

Schred86

Agreed. But if that was the case, I'd still be driving a stock z lol.

TXGS507

I recently did my H/C/I/E install on my 08Z... I too used the ATI 10% Damper... No issues as of yet.... ( knock on wood).