Broke at the track today
Thread Starter
Pro
Joined: Apr 2010
Posts: 651
Likes: 17
From: MD
Broke at the track today
Hey guys.. went to the track this morning after my cam swap that was finished up yesterday and ran 11.9 @ 119.7 my first run - bogged the launch with new MT et street radials. Then lined up for a second pass and tried to launch @ ~4k rpm while slipping the clutch slightly and it barely moved and just sat there and reved. almost like it popped out of gear or something so I stopped immediately to check if I was spewing fluid from the rear or something and everything is dry..
at first I thought for sure it had to be an output shaft but with the car running and i slowly release the clutch the car pulls slightly and then nothing with clutch fully out. It has an LS7 clutch that was installed only about 4-5 months ago. I would think if it was an output shaft the car wouldn't grab at all.
Any help would be appreciated!
at first I thought for sure it had to be an output shaft but with the car running and i slowly release the clutch the car pulls slightly and then nothing with clutch fully out. It has an LS7 clutch that was installed only about 4-5 months ago. I would think if it was an output shaft the car wouldn't grab at all.
Any help would be appreciated!
Thread Starter
Pro
Joined: Apr 2010
Posts: 651
Likes: 17
From: MD
thats one of the first things i checked .. popped the hood smelling for any clutch smell and there was none. a friend of mine said I might have ripped the face off the clutch, but wouldnt that make noise when released?
Last edited by Dave02C5; Oct 25, 2014 at 05:40 PM.
AMP Racing
Joined: Aug 2006
Posts: 10,755
Likes: 589
From: Washington TWP NJ
2023 C5 of the Year Finalist - Modified
2017 C5 of Year Finalist
St. Jude Donor '09-'10-'11-'12
The car will move with a broken output shaft. Very slowly and likely won't make it up any type of incline.
Replace with a C6Z shaft and get back out there to try again.
Replace with a C6Z shaft and get back out there to try again.
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
Jack ONE rear tire off the ground at a time and see if you can rotate the wheel. If you can, it's busted. Then do the other side.
Here are some REPAIR post for you. There just what you need!!
- C5, ragtopws6 , Upgrading your C5 rear with C6 Z06 guts, : http://forums.corvetteforum.com/c5-g...-z06-guts.html
-
- C5, Its_Go_Time, Output Shaft Install - Left and Right: http://forums.corvetteforum.com/c5-t...post1573407966
- C5 Differential Seal replacement: http://forums.corvetteforum.com/c5-g...on-photos.html
Bill
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Thread Starter
Pro
Joined: Apr 2010
Posts: 651
Likes: 17
From: MD
Thanks guys for all the help! So tomorrow I will check the diff and from what im reading its usually the longer ps side that snaps. Can I just get the shaft for that side or are both sides a problem?
AMP Racing
Joined: Aug 2006
Posts: 10,755
Likes: 589
From: Washington TWP NJ
2023 C5 of the Year Finalist - Modified
2017 C5 of Year Finalist
St. Jude Donor '09-'10-'11-'12
Typically, the short side shaft breaks first, but it could certainly be the long shaft.
Most might not agree with me, but, ask them how many passes they have with a stick car on the track.
I have broken several 300M shafts. I have twisted the splines on 300M shafts. My good racing buddy has also broken 300M shafts.
For what it's worth...
We have never broken a C6Z shaft. With well over 1000 passes between us.
The C6Z shafts will fit in your C5 diff. Also the clutch packs and the spring washer fit too. So it's a good upgrade.
Good luck with your repairs.
Most might not agree with me, but, ask them how many passes they have with a stick car on the track.
I have broken several 300M shafts. I have twisted the splines on 300M shafts. My good racing buddy has also broken 300M shafts.
For what it's worth...
We have never broken a C6Z shaft. With well over 1000 passes between us.
The C6Z shafts will fit in your C5 diff. Also the clutch packs and the spring washer fit too. So it's a good upgrade.
Good luck with your repairs.
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
FRIGGEN 100% SPOT ON! Sometimes its not the MOST EXPENSIVE thing that works.....
I did this MOD and it flat out works!
(for ME)
If I can do it, anyone can.. Its cost effective, and it works!
BC
I did this MOD and it flat out works!
(for ME)If I can do it, anyone can.. Its cost effective, and it works!
BC
Thread Starter
Pro
Joined: Apr 2010
Posts: 651
Likes: 17
From: MD
everything i read says the longer shaft breaks more than anything, which is probably why everyone sells it in 300M. if that is my case would I be able to just replace that single shaft without tearing into the small shaft side?
Intermediate
Joined: Oct 2014
Posts: 42
Likes: 1
Mine car did the same thing at the track a couple weeks ago after 2 wheel hops it just revved up but I was able to move the rest of the way done the track at about 3 mph as i revved it up in gear the speedo would accelerate so I know mine was not the clutch. Jacked up the rear end and only one tire would spin. I got a box of parts sitting next to me right now that I got of email from seller fatguyswithsuprattand300zxtt He built a kit for everything I was looking for with the Z06 output shafts and a complete rear end upgrade kit to go to the Z06 setup. I did look into the link with all the gm part numbers and it ended up being about 300 more for everything so gave this guy a shot and had all my parts 4 days earlier then expected and he let me use all his pinion shims and side shims to rebuild my rear end (for replacing gears) and he said to just send him back the shims I don't use.
Thread Starter
Pro
Joined: Apr 2010
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From: MD
Race Director
Joined: May 2004
Posts: 15,866
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From: PA
Sounds like you got relatively lucky that it was 'just' an output shaft. Worst damage to these cars appears to be breaking the trans housing where it meets the diff, that's real bad news. At least it shouldn't be too much work to replace a half shaft. Makes me wonder if it's even worth it to upgrade to a c6z half shaft though. If that isn't the weak link to let go under a hard launch something more expensive could....
Safety Car
Joined: Aug 2011
Posts: 4,449
Likes: 409
From: Portland OR
Just do both shafts with the C6 parts. Do the clutches and springs too. No doubt you have worn out clutches and at least one busted spring.
It's not that hard to do, and as long as it's out and apart, why not. Diff removal is a big job.
Ron
It's not that hard to do, and as long as it's out and apart, why not. Diff removal is a big job.
Ron