how to test differentials

[erecker]

I have a 91 AWD. I would like to test the differentials to make sure they are all working correctly. Correct me if I'm wrong - the front diff is open, the middle is viscous, and the rear is either open or lsd(depends on sticker).
How do you test to:
A) Make sure that the viscous is not burnt up
B) Make sure the rear LSD is not burnt up
C) Determine if you have an open or LSD rear end
D) Make sure all differentials are operating correctly

I saw a few years back a procedure for jacking the car up and spinning wheels by hand to ensure proper operation. I have searched both this site and others and have not found that post. It'd be nice to have this in the FAQ section because there's no use having AWD if it doesn't work...I'm sure that lots of higher mileage DSM's are starting to get burnt out diffs from wear, improper towing, etc.

Please let me know, thank you!
~Eric

 

[BUCK]

do you have a 92 also?

C) Determine if you have an open or LSD rear end

There's a Yellow Warning Sticker in the Drivers Door latch Panel, your VIN number has a clue also if the Sticker's gone - From everything I've seen virtually NO AWD's with ABS have the LSD Rear End - NONE - Personally I think ABS is a total waste on AWD anyway & it's a BIG PITA in the Engine Bay the way it takes up space.

There are answers to most of these other questions in the DSM Manual.

 

[srumel]

Hmm, I have a 92 Eclipse AWD w/ abs, and I have a rear lsd. It was also one of the rare 6 Bolt motor/ 4 bolt rear combos, until I replaced the engine with a jdm 6 bolt. Not that it matters though.

 

[Supa Dexta]

Yeah 6&4 here with awd/abs. I think from reading around, it was april 92 that they switched over and got abs to work with lsd.. And then like june 92 that the big brakes came?

 

[PieEyedPiper]

I have a 91 AWD. I would like to test the differentials to make sure they are all working correctly. Correct me if I'm wrong - the front diff is open, the middle is viscous, and the rear is either open or lsd(depends on sticker).
How do you test to:
A) Make sure that the viscous is not burnt up
B) Make sure the rear LSD is not burnt up
C) Determine if you have an open or LSD rear end
D) Make sure all differentials are operating correctly

I saw a few years back a procedure for jacking the car up and spinning wheels by hand to ensure proper operation. I have searched both this site and others and have not found that post. It'd be nice to have this in the FAQ section because there's no use having AWD if it doesn't work...I'm sure that lots of higher mileage DSM's are starting to get burnt out diffs from wear, improper towing, etc.

Please let me know, thank you!
~Eric

Maybe this is what you saw?
http://www.dsmtuners.com/forums/50388790-post4.html

 

[BUCK]

Yeah 6&4 here with awd/abs. I think from reading around, it was april 92 that they switched over and got abs to work with lsd.. And then like june 92 that the big brakes came?

COOL - you know as soon as I posted NONE I knew damn well there would be some pop up - Some things never change, even after 2000 Posts over 5 years - Merry Christmas, BUCK

 

[erecker]

PieEyedPiper: yes, that's the same test, but different wording. It'll tell me what I need to know though. Thanks!

It is registered as a 1992, built Nov.1991. I have several 1991 parts on it...
6 bolt, 23 spine, small brakes, 4 bolt rear

 

[steve]

The FSM test for the rear diff is to jack the car up and disconnect the driveshaft. If it has a rear VC for LSD and it's working you should be able to turn one wheel and the other should turn in the same direction. If you have an open diff or the VC is shot the other wheel will turn in the reverse direction.