I'm about to do a 3.90 LSD conversion for my "new" XT6. I have a few LSD rear differentials. Is there anyway to tell which LSD chunk is in the best condition before I swap?

Not really.

 

You cant really make enough resistance on a bench to heat the VC up enough for it to hook-up.

 

 

nipper

You cant really make enough resistance on a bench to heat the VC up enough for it to hook-up.

 

whoops - good point, this is for the EA/ER style clutch type LSD's. all EA/ER stuff is clutch type, no VLSD until the EJ stuff.

AH thats a entirely differnt animal. There is a procedure for using a torque wrench to measure the breaking torque. These operate completly differntly from VC. VC wait for wheel slip to engage, where as mechanical ones are engaged and wati for a torque differnce between wheels (like in a turn) to disengage.

 

But you need a FSM to do know the numbers. You can do it to all three on the bench, and just take the one with the highest torque rating.

 

nipper

i wonder when the DEA will drop in here based on the thread title

i wonder when the DEA will drop in here based on the thread title

 

So the proper responce should have been "the brown LSD is bad?"

 

 

So the proper responce should have been "the brown LSD is bad?"

 

 

 

I never had a problem with it,course that was 20 years ago.

Then it prolly wasn't brown!

Then it prolly wasn't brown!

 

 

i sort of remebmer rainbow colors myself, but then again the 80's are a bit hazy.

 

BTW "how to test an LSD" is NOT a good search phrase in google.

 

I was taught a torque wrench was used ona bench test after locking up the input and one axle shaft and seeing at what torque it breaks away.

 

But how hard is it to change the rear diff if you pick the wrong one. You can also pull off the rear cover and physically inspect it.

 

 

nipper

But how hard is it to change the rear diff if you pick the wrong one. You can also pull off the rear cover and physically inspect it.

i'm thinking i won't know the wrong one, they all "work", but i'd like the *best* one traction wise since this is a very functional upgrade for me. since it's for a 3.9 final drive ratio XT6 i'm having to convert one from open to LSD (the LSD's are all 3.7's) so actually it is a bit of work to swap. not just a matter of swapping boxes, which i would rather not do as well.

 

i looked it up in the FSM and couldn't find it. though I thought i recall seeing it some time in the past.

 

that's awesome! this title is a bit ridiculous!

Call an axle shop; if they have the specs to set up an R160 they probably know the breakaway torque.

http://www.gordon-glasgow.org/lsdtech.html

 

Does that help?

interesting page, aparently i have part # 38420-RS650 (4-pinion) R200 in mine but i was looking and H190 was available with a 5.429!?!?!

 

i wonder if its swapable with an R200