Did I break my Differential?
Thread Starter
Instructor
Joined: May 2003
Posts: 114
Likes: 1
From: Dallas Texas
Did I break my Differential?
I have a 2003 Z06 and am wondering if I broke something in the differential. This feels like a really stupid question but I just can't figure it out. With the car on the lift, all four wheels off the ground, and the transmission in gear I can easily, and I mean very easily, spin the rear wheels with my hand. What happens is what I would call "normal differential" behavior, that is, if I turn one wheel forward the other wheel spins backwards. There seems to be little or no resistance. Shouldn't the LSD or just something in the diff be trying to turn the transmission and thus the engine making it very difficult to turn the rear wheels on this manual transmission car?
Thanks for looking and replying and I want to apologize in advance for what feels like a very stupid question.
Dave
Thanks for looking and replying and I want to apologize in advance for what feels like a very stupid question.
Dave
Drifting
Joined: Feb 2006
Posts: 1,585
Likes: 15
From: New Hartford IA
Does it still drive without noise, etc? If so it might need some clutch packs and preload springs. As long as the gears are still nice and quiet it's not that bad to fix money wise if you are a do it yourself type.
Instructor
Joined: Jun 2008
Posts: 233
Likes: 1
From: Austin Texas
The car as described sounds normal to me. A limited slip differential allows the rear wheels to rotate relative to one another like any other differential for negotiating turns where the outer wheel travels a longer distance than the inner. However when one wheel loses traction the LSD locks up under hydraulic pressure allowing torque to transfer to the wheel with traction. The lockup is speed sensitive (relative rotation speed of rear wheels, not the car).
Last edited by Cratecruncher; Jan 8, 2011 at 08:03 PM.
Tech Contributor
Joined: Jan 2007
Posts: 19,424
Likes: 1,146
From: Dyer, IN
I have a 2003 Z06 and am wondering if I broke something in the differential. This feels like a really stupid question but I just can't figure it out. With the car on the lift, all four wheels off the ground, and the transmission in gear I can easily, and I mean very easily, spin the rear wheels with my hand. What happens is what I would call "normal differential" behavior, that is, if I turn one wheel forward the other wheel spins backwards. There seems to be little or no resistance. Shouldn't the LSD or just something in the diff be trying to turn the transmission and thus the engine making it very difficult to turn the rear wheels on this manual transmission car?
Thanks for looking and replying and I want to apologize in advance for what feels like a very stupid question.
Dave
Thanks for looking and replying and I want to apologize in advance for what feels like a very stupid question.
Dave
Thread Starter
Instructor
Joined: May 2003
Posts: 114
Likes: 1
From: Dallas Texas
When I change from street wheels/tire to the track set I've never had an issue removing lug nuts or installing/torquing with the car in the air. Now there is no way the wheels simply turn. Also at a track event last year I managed my first 360, well it was closer to a 540. It was one of those "I think it will hold..." as I dropped the outside tires off into the grass at about 110, I didn't get the clutch in quick enough, again like an idiot I was still in the "I think I can, I think I can...." frame of mind, by the time I came to a stop I was rolling backwards so I think the entire drive line received quite a shock. It really wasn't until I was getting both the C6 Z51 and the C5 Z06 both ready for a track event that it hit me that on the C6 it was impossible to turn the wheels with the car in the air and the C5 spins freely. And again this is the first time since 2003 that I have had to lower the car to the ground before I can torque rear lugs, so something seems different.
Dave
Dave
Last edited by David A; Jan 8, 2011 at 08:32 PM.
Le Mans Master
Joined: Dec 2008
Posts: 5,414
Likes: 25
From: Texas
it sounds like you might have some damage to the clutch pack in the differential....
is that what you are thinking?
get someone around you to give you a second opinion...and you can search on here for several posts about how to tear the diff down and replace the clutch pack in the diff....
good luck
is that what you are thinking?
get someone around you to give you a second opinion...and you can search on here for several posts about how to tear the diff down and replace the clutch pack in the diff....
good luck
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
I'm assuming from your description that the car is not drivable?
If you're in gear and can rotate the rear wheels, something is very wrong. You should be turning the engine over by turning the rear wheels. Possible problems include, torque tube bushing completely seperated (doubtful), tranny output shaft, very possible since the opposite wheel still turns in the other direction.
If you're in gear and can rotate the rear wheels, something is very wrong. You should be turning the engine over by turning the rear wheels. Possible problems include, torque tube bushing completely seperated (doubtful), tranny output shaft, very possible since the opposite wheel still turns in the other direction.
Drifting
Joined: Feb 2006
Posts: 1,585
Likes: 15
From: New Hartford IA
The wheels will spin in the oppisite direction like an open differential WITH the transmission in gear if the damn clutch packs are fried. Simple as that. The ring and pinion can't turn, but the small gears inside the diff carrier can turn easy if they have no clutch load on them.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Instructor
Joined: Jun 2008
Posts: 233
Likes: 1
From: Austin Texas
I'll have to buck consensus here. Spinning the rear wheels by hand is not a valid test. Without load the LSD acts like an open diff. Torque is required to squeeze the clutches disks together and angular speed is needed for the fluid's viscosity to work. There are however accurate ways to assess the condition of the LSD without disassembly. I'd recommend the OP consult a knowledgeable specialist before concluding the unit is damaged.
Melting Slicks
Joined: Dec 2003
Posts: 3,315
Likes: 17
From: Near Jacksonville Fl.
I'll have to buck consensus here. Spinning the rear wheels by hand is not a valid test. Without load the LSD acts like an open diff. Torque is required to squeeze the clutches disks together and angular speed is needed for the fluid's viscosity to work. There are however accurate ways to assess the condition of the LSD without disassembly. I'd recommend the OP consult a knowledgeable specialist before concluding the unit is damaged.
The clutch pack has a preload and break away torque is ~300lb ft.
He has failed the belleville springs and probably the clutches too.
Le Mans Master
Joined: Dec 2008
Posts: 5,414
Likes: 25
From: Texas
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
Yup, as a minimum you broke the pre-load spring.
The unit in the Vette has clutches and a preload spring so the clutches are loaded all the time.
GM did use a Gov-Lok or G-80 diff in some cars and trucks and that one used a weight and gears to lock. It worked like an open diff when you slowly spun the wheels. But, the Vette does not use one of these.
I've never heard of an automatic limited slip diff that used hydraulic pressure to lock before.
Peter
The unit in the Vette has clutches and a preload spring so the clutches are loaded all the time.
GM did use a Gov-Lok or G-80 diff in some cars and trucks and that one used a weight and gears to lock. It worked like an open diff when you slowly spun the wheels. But, the Vette does not use one of these.
I've never heard of an automatic limited slip diff that used hydraulic pressure to lock before.
Peter
Thread Starter
Instructor
Joined: May 2003
Posts: 114
Likes: 1
From: Dallas Texas
Just a followup in the event this thread is useful for someone in the future doing a search. RAGTOPWS6 is 100% correct. I was finally able to pull my LSD apart today and the cone washer is broken exactly like shown.
Thanks for all the help,
Dave
Thanks for all the help,
Dave
Melting Slicks
Joined: Feb 2003
Posts: 2,966
Likes: 22
From: Frederick Maryland
St. Jude Donor '08-'09-'10-'11
