What's a good way to check a diff?

[Mr.SWISS]

I think the diff is no good but only under load. Is there a way to check the clutches for slippage without ripping the cover off?

[jlevie]

Jack up the driver's rear wheel, take the parking brake off, and put the transmission in neutral. Then, using a torque wrench, see how much force is required to cause the driver's wheel to turn. And LSD in good condition will take better than 50ft-lb of torque before the wheel will turn.

[Mr.SWISS]

Jack up the driver's rear wheel, take the parking brake off, and put the transmission in neutral. Then, using a torque wrench, see how much force is required to cause the driver's wheel to turn. And LSD in good condition will take better than 50ft-lb of torque before the wheel will turn.

On it.

[samiam3356]

Post results if you will


Going to try mine this week. Its a fresh LSD the is smooth and locks predictably and smoothly.

[Mr.SWISS]

About 25-30ftlbs and it spins.......

I tried to pinpoint it under the car running but it only seems to have make the noise under load.

[Jaxx_]

I'll be doing this this weekend just to see how good my LSD is performing.

[samiam3356]

Guess I don't understand why this test is useful. Doesn't the LSD need a load to lock. So jacking up the car and doing what was said wouldn't place enough load to lock it IMO but maybe it does. Just having a hard time believing this test is really worth while. Maybe, meh

[jlevie]

It works because one wheel is locked by it resting on the ground. So what you are measuring is how much force is required to cause the clutches to slip.

BTW: a new E30 differential should hold 65ft-lb before the clutches slip.

[samiam3356]

aight, I misread your post then. I'm seeing the whole rear jacked up not just one wheel. lol Thanks for the clarification Jim

[Steeler325is]

Interesting...

[Cronopoulos]

Do a burnout.

[Jaxx_]

56 ft/lbs until it broke loose.

[jlevie]

56 ft/lbs until it broke loose.

That is a pretty good set of clutches. It could be better, but not worth rebuilding at this point.

[Bearmw]

And to clarify the torque wrench should be measuring the torque at the axle nut and not a lug nut right?

[b*saint]

I would think so. If you do it on a lug nut, then you are adding leverage. So 56 could possibly be 60+