Damper spinning off crank...
Thread Starter
Racer
Joined: Jan 2012
Posts: 398
Likes: 22
From: Las Vegas NV
Damper spinning off crank...
Its happened twice now. ATI super damper, ARP bolt. Driving me up the fricken wall.
HCI car...480rwhp/430rwtq
I know I'll catch hell for install error but followed directions to a damn T both times. ARP lube the first time. Used red loctite the 2nd time. Didn't matter. Went about 1000 miles both times.
Just ordered ATI's pin kit. What's the theory on the pin kit? Even if a 4xxrwhp motor is causing the damper to spin, how the hell is it backing off a loctite'd, 240ftlb crank bolt?? Read about it...didn't think I'd need it, thought pinning was for blower cars due to belt wrap, power etc etc
Any similar issues with happy endings after pinning the damn thing?
Can you pin the crank with the front cover still on with the side pin kit like ATI's?
Thanks in advance
HCI car...480rwhp/430rwtq
I know I'll catch hell for install error but followed directions to a damn T both times. ARP lube the first time. Used red loctite the 2nd time. Didn't matter. Went about 1000 miles both times.
Just ordered ATI's pin kit. What's the theory on the pin kit? Even if a 4xxrwhp motor is causing the damper to spin, how the hell is it backing off a loctite'd, 240ftlb crank bolt?? Read about it...didn't think I'd need it, thought pinning was for blower cars due to belt wrap, power etc etc
Any similar issues with happy endings after pinning the damn thing?
Can you pin the crank with the front cover still on with the side pin kit like ATI's?
Thanks in advance
Burning Brakes
Joined: Mar 2014
Posts: 807
Likes: 239
Its happened twice now. ATI super damper, ARP bolt. Driving me up the fricken wall.
HCI car...480rwhp/430rwtq
I know I'll catch hell for install error but followed directions to a damn T both times. ARP lube the first time. Used red loctite the 2nd time. Didn't matter. Went about 1000 miles both times.
Just ordered ATI's pin kit. What's the theory on the pin kit? Even if a 4xxrwhp motor is causing the damper to spin, how the hell is it backing off a loctite'd, 240ftlb crank bolt?? Read about it...didn't think I'd need it, thought pinning was for blower cars due to belt wrap, power etc etc
Any similar issues with happy endings after pinning the damn thing?
Can you pin the crank with the front cover still on with the side pin kit like ATI's?
Thanks in advance
HCI car...480rwhp/430rwtq
I know I'll catch hell for install error but followed directions to a damn T both times. ARP lube the first time. Used red loctite the 2nd time. Didn't matter. Went about 1000 miles both times.
Just ordered ATI's pin kit. What's the theory on the pin kit? Even if a 4xxrwhp motor is causing the damper to spin, how the hell is it backing off a loctite'd, 240ftlb crank bolt?? Read about it...didn't think I'd need it, thought pinning was for blower cars due to belt wrap, power etc etc
Any similar issues with happy endings after pinning the damn thing?
Can you pin the crank with the front cover still on with the side pin kit like ATI's?
Thanks in advance
Melting Slicks
Joined: Nov 2008
Posts: 2,938
Likes: 65
From: Rochester Hills MI
the ati tool is designed to be used with the cover on. here are the instructions:
http://www.atiracing.com/instructions/918993.pdf
http://www.atiracing.com/instructions/918993.pdf
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Did you measure the crank and the hub of the ATI prior to installation? I wouldn't use red loctite, it is a bandaid for a bigger problem. The pin kit is a very good quality kit, but it sounds like your interference fit is not correct. Do you have the tools to measure down to 1/10,000 inch?
Burning Brakes
Joined: Dec 2009
Posts: 927
Likes: 6
From: King George VA
My ARP crank bolt spun out (as did my brand new GM damper) while staging for the parade at Carlisle this past year. Upon install, i used the ARP lube and didn't bother to pin the snout. The damper moved out against the steering rack and chewed itself up pretty badly. Luckily, thats the only damage it caused (besides burning up both belts) and it happened at idle; Just two hours earlier I did a rather dangerous highway pull so it could have been MUCH worse!
After the damper backed off, I started the car just long enough to get the car on a trailer to bring it home (4+ hours South). I immediately ordered an ATI pin kit with a Powerbond 25% underdrive. I torqued it to 250lbs instead of 240lb just for that extra teeny ounce of insurance. I used blue loctite and pinned it and I haven't had any trouble since.
A few times, i've been told to not use the ARP lube on the threads of the bolt, but only on the bearing faces of the washer and bolt. Hang in there, man. It's a stressful situation but it'll be okay!
After the damper backed off, I started the car just long enough to get the car on a trailer to bring it home (4+ hours South). I immediately ordered an ATI pin kit with a Powerbond 25% underdrive. I torqued it to 250lbs instead of 240lb just for that extra teeny ounce of insurance. I used blue loctite and pinned it and I haven't had any trouble since.
A few times, i've been told to not use the ARP lube on the threads of the bolt, but only on the bearing faces of the washer and bolt. Hang in there, man. It's a stressful situation but it'll be okay!
Thread Starter
Racer
Joined: Jan 2012
Posts: 398
Likes: 22
From: Las Vegas NV
Did you measure the crank and the hub of the ATI prior to installation? I wouldn't use red loctite, it is a bandaid for a bigger problem. The pin kit is a very good quality kit, but it sounds like your interference fit is not correct. Do you have the tools to measure down to 1/10,000 inch?
I guess a positive is I can yank the rack out in less than an hour
You might check the depth of the threaded hole in the crank snout and compare it to the length of the bolt. If the bolt is bottoming out in the snout, harmonics between the bolt and damper (since it technically wouldn't be clamping the damper) may be causing the bolt to back out
I immediately ordered an ATI pin kit with a Powerbond 25% underdrive. I torqued it to 250lbs instead of 240lb just for that extra teeny ounce of insurance. I used blue loctite and pinned it and I haven't had any trouble since.
Thanks for the reply's
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
A very good friend let me borrow his ATI Crank pinning kit. I thought it would be a difficult job but, to my surprise, it was really easy. I agree, "It can be accomplished with the front cover in place.
The PIN fits inside the POWERBOND Damper snout and prevents the damper from spinning on the crank snout.
Here's a picture of the Powerbond key way:
I TOO used the ARP BOLT at 240 ft/lbs and I have NOT had any issues.
I also agree on measuring the interference fit between the damper and the crank snout.
BC
The PIN fits inside the POWERBOND Damper snout and prevents the damper from spinning on the crank snout.
Here's a picture of the Powerbond key way:
I TOO used the ARP BOLT at 240 ft/lbs and I have NOT had any issues.
I also agree on measuring the interference fit between the damper and the crank snout.
BC
Last edited by Bill Curlee; Dec 8, 2015 at 06:56 PM.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
I wouldn't give up the ATI for a PB. However, you should verify you also have the correct ATI damper. The f-body looks very similar so it might be worth the few minutes to verify the part number. Also, if you want extra insurance and have the time, ATI will machine a second keyway in the hub opposite to th existing one so you can double pin (note that the kit is set up to do this as well). This is recommended for FI installations but it might be a better way of getting that extra insurance you are seeking as opposed to using Loctite.
Last edited by vettenuts; Dec 8, 2015 at 06:47 PM.
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Thread Starter
Racer
Joined: Jan 2012
Posts: 398
Likes: 22
From: Las Vegas NV
Update: if it helps anybody, pinning the crank seems to have solved it. Used the ATI pin kit and installed a new ARP bolt to spec. 2000mi and the bolt hasnt moved at all(paint marker'd bolt to damper as reference). Held up to a dozen n2o pulls(7000rpm) at a 1/2 mile event, dyno runs and the street miles. Never came close to lasting this long prior to pinning the crank.
Appreciate the tips!
Appreciate the tips!
Last edited by Cheesecake 07; Mar 30, 2016 at 03:21 AM.
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,441
Likes: 2,186
From: Buffalo Texas
Did you measure the crank and the hub of the ATI prior to installation? I wouldn't use red loctite, it is a bandaid for a bigger problem. The pin kit is a very good quality kit, but it sounds like your interference fit is not correct. Do you have the tools to measure down to 1/10,000 inch?
Melting Slicks
Joined: Nov 2009
Posts: 2,922
Likes: 219
From: West Branch, MI
Wouldn't it have been nice if GM had simply keyed the balancer and the crank instead of having to go through all of this? They did on later models. I guess they were learning as they went along.
Drifting
Joined: Aug 2006
Posts: 1,719
Likes: 1
From: Florida
St. Jude Donor '07
I wasn't aware of the change on later models. Do you have any other details?
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,441
Likes: 2,186
From: Buffalo Texas