• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Limited Slip??

JoesXJ

NAXJA Forum User
Location
California
How do you tell if you have a limited slip rear end? I thought I might have one so I went to a dirt lot and stomped on the gas....left 2 lines. Still curious I sat there and did a brake stand...looked out driver window and tire is spinning, left 2 holes where back tires where. Is this an accurqate way of telling yes or no, if not, how??
 
Lift rear off ground and spin one tire by hand, if the other tire turn opposite direction it's open. If it spins same diretion then there is a traction device.
There should also be a metal tage on the diff. You can also go to the jeep site and punch in your vin, it will give you a printout of the jeep as it came from the factory.
 
RichP said:
You can also go to the jeep site and punch in your vin, it will give you a printout of the jeep as it came from the factory.

Bear in mind that will only help you if you're sure any previous owner hasn't changed anything.

Sarge
 
Actually its possible to have the tires spin in the same direction with an open differential, unlikely in a RWD live axle setup, but very common in FWD manual transaxles.

In addition to the above check, I'd also check; with the rear tires off the ground, put the transmission in "Park" for an Auto, "1st Gear" for a Manual, turn one tire, if the other tire turns the opposite direction, its an "OPEN" Differential, if the tires don't turn at all or turn only with signficant resistance, its a "Limited Slip" Differential. Have another person try to hold or turn the opposite wheel, if you can get the wheels to turn independently of each other with little or no effort, its an "OPEN" Diff, if the wheels fight you and act locked together, its a "Limited Slip" Diff.

A "Limited Slip" Diff, just has clutch packs between the wheels, so it lets the wheels spin independently, but only with a lot of resistance.

Even though an "OPEN" Diff only transmitts power to one wheel, it is possible for it to transmitt power to both wheels for a few moments, if both wheels start at the same speed and the traction is perfectly even inbetween them. Many people with an "OPEN" Diff can spin tires a little from a stop and leave 2 tire tracts for a few feet. After a few feet, one wheel will start spinning more than the other, and one tire tract may be longer than the other.

"Locker" Differentials actually have teeth in them that engage to LOCK the two wheels together. I think those are only aftermarket on Jeeps, could be wrong though. The "Locker" Diffs can be manually unlocked or the teeth can be spring loaded to pop out of lock if the forces between the tires are great enough, to let them turn independently.
 
Last edited:
Rick Anderson said:
In addition to the above check, I'd also check; with the rear tires off the ground, put the transmission in "Park" for an Auto, "1st Gear" for a Manual, turn one tire, if the other tire turns the opposite direction, its an "OPEN" Differential, if the tires don't turn at all or turn only with signficant resistance, its a "Limited Slip" Differential. Have another person try to hold or turn the opposite wheel, if you can get the wheels to turn independently of each other with little or no effort, its an "OPEN" Diff, if the wheels fight you and act locked together, its a "Limited Slip" Diff.

A "Limited Slip" Diff, just has clutch packs between the wheels, so it lets the wheels spin independently, but only with a lot of resistance.
This check only works for clutch-type limited slips, which is what the factory Trac-Lok is. An aftermarket gear-driven unit like a TrueTrac or Torsen will appear to work like an open diff when subjected to the "jack it up and spin the tires by hand" test.

Also, on a high mileage vehicle, a worn-out Trac-Lok will also behave like an open diff.
 
Back
Top