8.8 LSD Test

[crouse]

A friend of mine was telling me about a test he used to run on limited slip differentials. He said you raise one wheel then try to breakaway that wheel using a torque wrench? If the breakaway is above a certain torque, then your LSD is ok. If it's below a certain torque, then the clutches need to be replaced. Has anyone heard of this? Any ideas how to measure the torque and what the torque number is?

[RacerX]

Yep. 20lbs is within lowest end of spec, but, you want between 80 to 100 ft lbs. If you throw an extra clutch plate on each side in there, you can get her to 300lbs. May shudder a little on turns though! :D

[crouse]

Thanks for the info. I'm thinking it should be close to the center of the axle when measuring the torque. How do you connect the torque wrench to the axle or wheel? Can you get an accurate torque reading by putting the torque wrench on one of the lug nuts?

[RacerX]

Hmmmm... Good question! There must be something to put in the end of the axle hub. You have to figure to that the break away torque value is of the combined assembly (friction of bearings, brakes, gears, and LSD with lubricant).

[WI Fordguy]

I wonder if someone could use the hub puller attachment of a slide hammer somehow, then you would be turning from center mass and using 3 lug nuts.

[ImpalaSlayer]

seems like it would be easy to make a tool to do such. some 1/4 plate and a bolt