How to tell if LSD is working?
10-21-2017, 09:50 AM
#1
TECH Addict
Thread Starter
How to tell if LSD is working? I bought a ‘99 6 speed z28 a few weeks back. Had it up on the ramps today at a workshop.
They seemed to think it had no LSD. How can I tell if it does or not? I know it should. But no idea if it’s working, broken or missing.
While on the high lift in neutral if you spin a rear wheel it would only spin the driveshaft. Not the other wheel. Same on both sides.
If I held the driveshaft spinning one wheel forwards would make the other spin backwards.
Have tried wheel spinning from a start, but the tarmac round here doesn’t show tyre marks. So I can’t tell if it’s spinning both wheels or just one.
They seemed to think it had no LSD. How can I tell if it does or not? I know it should. But no idea if it’s working, broken or missing.
While on the high lift in neutral if you spin a rear wheel it would only spin the driveshaft. Not the other wheel. Same on both sides.
If I held the driveshaft spinning one wheel forwards would make the other spin backwards.
Have tried wheel spinning from a start, but the tarmac round here doesn’t show tyre marks. So I can’t tell if it’s spinning both wheels or just one.
10-22-2017, 01:56 AM
#2
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All '99+ LS1 F-bodies received a Torsen LSD (unless it was an SLP car ordered with the optional Auburn....which would not be the case for a base model Z28 such as yours.) The Torsen is quite different from the base Auburn rears of the 1998 and earlier models, in that it will spin the wheels in opposite directions (like an open rear) when unloaded (as you have witnessed above.)
I'm not sure how, if even possible, to test it for proper operation in an unloaded state as I've never needed to. If it has failed, in my experience it's usually pretty obvious based on the behavior/feel of the rear during tire spin from a stop.
I'm not sure how, if even possible, to test it for proper operation in an unloaded state as I've never needed to. If it has failed, in my experience it's usually pretty obvious based on the behavior/feel of the rear during tire spin from a stop.
10-22-2017, 02:57 AM
#3
When I read the title "How to tell if LSD is working?" it gave me flashbacks lol
The old answer would have been when you're seeing **** you know can't be real!
Seriously though if it doesn't leave marks you need to get more heat in the tires = spin them longer, Or do what people have done in the past, Get some white shoe polish and put a few stripes across the tread on the tires and let it dry completely. Then do your burn out, If the tire doesn't spin it won't wear off the shoe polish.
The old answer would have been when you're seeing **** you know can't be real!
Seriously though if it doesn't leave marks you need to get more heat in the tires = spin them longer, Or do what people have done in the past, Get some white shoe polish and put a few stripes across the tread on the tires and let it dry completely. Then do your burn out, If the tire doesn't spin it won't wear off the shoe polish.
Last edited by LLLosingit; 10-22-2017 at 03:05 AM.
10-22-2017, 03:00 PM
#4
It's not a great method, but what most people do will be to leave one wheel on the ground and lift the other side. Best to use a beam style torque wrench and try to turn the wheel that is in the air. If using it on a lug you will have to account for that but you should still be able to measure break-away torque.
When driving, just turn hard right and get on the gas. If the car goes forward it is working. If it just makes noise it's not.
Example of when it's not working, you can hear the revs climb but the car doesn't go anywhere (go to 1:08 mark):
When driving, just turn hard right and get on the gas. If the car goes forward it is working. If it just makes noise it's not.
Example of when it's not working, you can hear the revs climb but the car doesn't go anywhere (go to 1:08 mark):
Last edited by landstuhltaylor; 10-22-2017 at 03:05 PM.