Did the PO add a locker to this rear end. The jeep spins both rear tires when on the slick (2000 Sahara 120k 6cyl 5 speed). The build sheet from Chrysler says it was built with a DANA 44. It does not say anything about it being a "true trac" on the build sheet. Upon inspection it looks as if there has been tampering with the bolts. There was an aftermarket on/off lit electric switch on the dash that only had a ground going to it. The switch was broken and the ground was barly attached. Could not find the accessories wire that once powered the switch. There is no aftermarket electronics on the Jeep with the exception of a winch. My question is could there be a locker (electric or Detroit) in the rear end and how would I find out without doing unnecessary investigative surgery on the rear end?
What did previous owner do to rear end?
- Thread starter EROCK
- Start date
Both tires can spin even if there is no locker or LSD if traction conditions are equal under both tires. Even an open differential splits the torque delivered to both sides exactly 50:50 every time. All the time, no matter what. 
Best thing you can do is change the fluid in that differential. (You should do that anyway if you don't know when it was changed) Once you have the cover off take a picture and post it.
Someone experienced with locker behavior could tell by how it drives if there's an automatic locker present. But if there was an automatic locker installed, you'd know it since they don't drive normally until you learn how to drive a bit differently. If a selectable locker has been installed, one that can be turned on & off while driving, there would either be electrical wiring or an air line leading into the axle (don't confuse that with its normal rubber air vent hose that connects to the axle tube), or a heavy steel cable connected to a lever inside the passenger compartment.
Or there could be a Detroit Truetrac inside which is a limited slip differential. Or the factory Tracloc limited slip differential. Neither drive differently enough to be able to know if they're there or not.
Pulling the cover and posting a good clear photo of what's inside is the best way to find out what's inside.
801 Driver
TJ Enthusiast
First, I know nothing about lockers other than the old Chevy positracs, but if I were starting to take a look at what I might have to learn more without taking the cover off, I would find a place I could put one wheel on dry pavement and the other in dirt, gravel, ice or mud and see if one or both sides gripped or slipped with a quick launch.
And/or I would safely block the wheels, transmission in neutral. Jack up one rear wheel and see how it turns the drive shaft by hand. Others here most likely can add to this of how the various lockers would feel or sound if it is the ratchet type I think I have seen, to do a little narrowing down of what you might have.
Good luck with your research project. Tell us more of what you try and find so us newbies will have more info we might use in the future.
And/or I would safely block the wheels, transmission in neutral. Jack up one rear wheel and see how it turns the drive shaft by hand. Others here most likely can add to this of how the various lockers would feel or sound if it is the ratchet type I think I have seen, to do a little narrowing down of what you might have.
Good luck with your research project. Tell us more of what you try and find so us newbies will have more info we might use in the future.
John Scoggins
TJ Enthusiast
Here is one way to check for a locker:
- Jack up rear end
- Put transmission in Park
- Rotate the drivers side wheel forward and hold against the driveline
- Try to rotate the passenger side wheel in the forward direction while holding the dirvers side in step 3 (will need a helper), if there is a locker then the passenger side wheel will not rotate.
- If the passenger wheel will not move from step 4, sharply rotate the passenger wheel in reverse, this will unlock the locker and you will be able to spin the passenger side wheel and will hear clicking from the rear end.
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That's really not how it works, you don't need a Positrac (which is not a locker, it's a limited slip differential) to make both tires spin while accelerating. Even an open axle with no LSD or locker can spin both tires at once with equal traction under each tire. Open and LSD-equipped axles always (always!) split the torque exactly 50:50 between the left and right tires. That may be surprising but it's absolutely true.