Clutch pack
Le Mans Master
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Race Director
Joined: Dec 2013
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LSD clutch packs have a 100ftlb break away value, if you use the correct fluid.
You use something like Redline as your diff fluid, it lowers the break away value to cause peg leg burn outs instead.
As for road course use since I can burn out the LSD clutch packs in under 18K, run the Quaife mech type locks instead.
So short of wrong fluid used, and something in the packs went south from either abuse or just wear over time, standard LSD friction disc should be fine for your use. If you want to still stay with friction discs for strip use, then there are some better pressure compound discs (cf) that will take more abuse until you do wear them out. As for going to spooled diff, not a good idea for any street use where you have to go around corners and don't want the rear tires locked together.
As for checking the LSD disc's break away values, car in gear or park, choke the front tires, bring just one rear side at a time, set a torque wrench to 100ftlbs, and with 33/34mm socket (depending if your axle nuts are the old type or not), tighten the axle nut to make sure it/the axle is not spinning until the wrench clicks at 100ftlbs. If axle spins before this, then wrong diff fluid that is too slick, or the clutch packs are cooked.
Note, wrong diff fluid used too long, just causes the clutch pad discs to wear out a hell of lot faster since the break away value it too low to begin with,and pretty much slipping all the time even the lightest off corning.
You use something like Redline as your diff fluid, it lowers the break away value to cause peg leg burn outs instead.
As for road course use since I can burn out the LSD clutch packs in under 18K, run the Quaife mech type locks instead.
So short of wrong fluid used, and something in the packs went south from either abuse or just wear over time, standard LSD friction disc should be fine for your use. If you want to still stay with friction discs for strip use, then there are some better pressure compound discs (cf) that will take more abuse until you do wear them out. As for going to spooled diff, not a good idea for any street use where you have to go around corners and don't want the rear tires locked together.
As for checking the LSD disc's break away values, car in gear or park, choke the front tires, bring just one rear side at a time, set a torque wrench to 100ftlbs, and with 33/34mm socket (depending if your axle nuts are the old type or not), tighten the axle nut to make sure it/the axle is not spinning until the wrench clicks at 100ftlbs. If axle spins before this, then wrong diff fluid that is too slick, or the clutch packs are cooked.
Note, wrong diff fluid used too long, just causes the clutch pad discs to wear out a hell of lot faster since the break away value it too low to begin with,and pretty much slipping all the time even the lightest off corning.
Last edited by Dano523; Apr 29, 2022 at 05:07 PM.
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Joined: Jul 2019
Posts: 91
Likes: 10
LSD clutch packs have a 100ftlb break away value, if you use the correct fluid.
https://www.amazon.com/ACDelco-10-40.../dp/B008BZS6J8
You use something like Redline as your diff fluid, it lowers the break away value to cause peg leg burn outs instead.
As for road course use since I can burn out the LSD clutch packs in under 18K, run the Quaife mech type locks instead.
So short of wrong fluid used, and something in the packs went south from either abuse or just wear over time, standard LSD friction disc should be fine for your use. If you want to still stay with friction discs for strip use, then there are some better pressure compound discs (cf) that will take more abuse until you do wear them out. As for going to spooled diff, not a good idea for any street use where you have to go around corners and don't want the rear tires locked together.
As for checking the LSD disc's break away values, car in gear or park, choke the front tires, bring just one rear side at a time, set a torque wrench to 100ftlbs, and with 33/34mm socket (depending if your axle nuts are the old type or not), tighten the axle nut to make sure it/the axle is not spinning until the wrench clicks at 100ftlbs. If axle spins before this, then wrong diff fluid that is too slick, or the clutch packs are cooked.
Note, wrong diff fluid used too long, just causes the clutch pad discs to wear out a hell of lot faster since the break away value it too low to begin with,and pretty much slipping all the time even the lightest off corning.
https://www.amazon.com/ACDelco-10-40.../dp/B008BZS6J8
You use something like Redline as your diff fluid, it lowers the break away value to cause peg leg burn outs instead.
As for road course use since I can burn out the LSD clutch packs in under 18K, run the Quaife mech type locks instead.
So short of wrong fluid used, and something in the packs went south from either abuse or just wear over time, standard LSD friction disc should be fine for your use. If you want to still stay with friction discs for strip use, then there are some better pressure compound discs (cf) that will take more abuse until you do wear them out. As for going to spooled diff, not a good idea for any street use where you have to go around corners and don't want the rear tires locked together.
As for checking the LSD disc's break away values, car in gear or park, choke the front tires, bring just one rear side at a time, set a torque wrench to 100ftlbs, and with 33/34mm socket (depending if your axle nuts are the old type or not), tighten the axle nut to make sure it/the axle is not spinning until the wrench clicks at 100ftlbs. If axle spins before this, then wrong diff fluid that is too slick, or the clutch packs are cooked.
Note, wrong diff fluid used too long, just causes the clutch pad discs to wear out a hell of lot faster since the break away value it too low to begin with,and pretty much slipping all the time even the lightest off corning.
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Joined: Dec 2013
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Again, No on the redline fluid, since its too slick, and lowers the break away values on the clutch packs.
Here is the correct fluid,
So get the correct fluid in the diff (buy 4 quarts), go find a larger parking lot to do slow figure 8's both ways to flush the clutch packs of the old fluid, get the new fluid into the packs, then break out the torque wrench to check the break away values of the clutch packs both sides.
If below 100ftlbs, then go do some more slow figure 8's to make sure you have the old fluid flushed out, and retest again. If still below 100ft lbs, then diff has to come apart to replace the clutch pads that have worn out instead.
As for LSD clutch packs for the C6 differ, just look up diff racing clutch packs, and there are slew of carbon clutch packs that will last longer than the OEM packs. Hell, look hard enough, and you can find a LSD clutch pack that will spool the diff as well.
Here is the correct fluid,
So get the correct fluid in the diff (buy 4 quarts), go find a larger parking lot to do slow figure 8's both ways to flush the clutch packs of the old fluid, get the new fluid into the packs, then break out the torque wrench to check the break away values of the clutch packs both sides.
If below 100ftlbs, then go do some more slow figure 8's to make sure you have the old fluid flushed out, and retest again. If still below 100ft lbs, then diff has to come apart to replace the clutch pads that have worn out instead.
As for LSD clutch packs for the C6 differ, just look up diff racing clutch packs, and there are slew of carbon clutch packs that will last longer than the OEM packs. Hell, look hard enough, and you can find a LSD clutch pack that will spool the diff as well.
Thread Starter
Advanced
Joined: Jul 2019
Posts: 91
Likes: 10
Again, No on the redline fluid, since its too slick, and lowers the break away values on the clutch packs.
Here is the correct fluid,
So get the correct fluid in the diff (buy 4 quarts), go find a larger parking lot to do slow figure 8's both ways to flush the clutch packs of the old fluid, get the new fluid into the packs, then break out the torque wrench to check the break away values of the clutch packs both sides.
If below 100ftlbs, then go do some more slow figure 8's to make sure you have the old fluid flushed out, and retest again. If still below 100ft lbs, then diff has to come apart to replace the clutch pads that have worn out instead.
As for LSD clutch packs for the C6 differ, just look up diff racing clutch packs, and there are slew of carbon clutch packs that will last longer than the OEM packs. Hell, look hard enough, and you can find a LSD clutch pack that will spool the diff as well.
Here is the correct fluid,
So get the correct fluid in the diff (buy 4 quarts), go find a larger parking lot to do slow figure 8's both ways to flush the clutch packs of the old fluid, get the new fluid into the packs, then break out the torque wrench to check the break away values of the clutch packs both sides.
If below 100ftlbs, then go do some more slow figure 8's to make sure you have the old fluid flushed out, and retest again. If still below 100ft lbs, then diff has to come apart to replace the clutch pads that have worn out instead.
As for LSD clutch packs for the C6 differ, just look up diff racing clutch packs, and there are slew of carbon clutch packs that will last longer than the OEM packs. Hell, look hard enough, and you can find a LSD clutch pack that will spool the diff as well.
