how to tell if limited slip

purevil115 · 12-19-2009, 09:08 PM

Ok so now that snows falling I see my rear end the wheels spin together no matter what. I am not sure if its limited slip though. Its a 99 sahara and from what I can tell its got a ton of options like cruise and tilt(not that that matters just saying someone spent money when new). Is there a rpo code or anything I can look up in it to tell? If i pull the back cover and change the fluid will I see the srpings and everything?

purevil115 · 12-19-2009, 09:11 PM

Also trying to find out what gear ratio I have is there a way to tell?

ET48 · 12-19-2009, 09:14 PM

I'm not sure about a code. If you change the fluid you can easily see if there is limited slip or not.

Open diff looks like this with spider gears:

Limited slip looks like the one on the right (Another open on the left):

ET48 · 12-19-2009, 09:16 PM

Quote:

Originally Posted by purevil115

Also trying to find out what gear ratio I have is there a way to tell?

Gear ratio can be found on the differential tag if it is stock gearing. If it maybe has been changed, you best count the teeth on the ring and pinion to find the ratio. # teeth on the ring divided by the # of teeth on the pinion gives you the ratio.

You can also count the revolutions of the driveshaft per one revolution of the tire. (Both tires must turn at the same time to do this)

sonoran_Tj · 12-19-2009, 09:18 PM

Your differential should have one or two metal tags bolted on to it. The one that should be there says what your diff gearing is. I also have one that warns me to only use diff oil with an additive for a lsd, which I have.

purevil115 · 12-19-2009, 10:04 PM

Is there anyway to tell from inside. Its snowing bad and dont want to climb under it but very curious

too_old_to_care · 12-19-2009, 11:15 PM

Jack up the rear so both wheels are off the ground and spin one tire; if it has limited slip both wheels will turn the same direction, if it is open (no limited slip) the wheels will rotate in opposite directions.

While it's in the air you can get a close approximation of the ratio by carefully marking the tire and drive shaft, then turn the wheel EXACTLY one revolution and count how many times the drive shaft turns. There's your ratio.

rs4race · 12-19-2009, 11:41 PM

Get a build sheet from jeep!

It takes about a week. They email them now. Or there should be a metal tag on the diff. It might be hidden under a bunch of road grime!

But from what I have read they are completely worthless before you hit 90k.(worn out) But the rebuild kit is just under $60. This will probably be the next thing I do on the jeep.

rs4race · 12-19-2009, 11:43 PM

Gear ratio's should also be marked on a tag on your diff. There is a tag on the front and the rear FYI. migh have to do some cleaning to find it tho. I did.

MisterO · 12-20-2009, 01:10 AM

X2 on lifting the rear and turning one wheel, if the other goes in the same direction LSD, if not then open diff..

for gears, prob 3.73 since its a sahara and a 99.. but then again every jeep is different.. look at the tag or ask for a BUILD SHEET .. <-----Click Here-----<

brianangst · 12-20-2009, 01:27 AM

not to hijack this thread, but what if there is a locker in the rear? If you lift the rear of the Jeep up and spin a wheel, do both wheels spin the same direction? I don't know if I have a lsd or a locker in my jeep. I have a ford 8.8 that the po said has a locker, but when I asked if it could be the factory LSD he said he did not know anything about lockers, he was not sure which it was.

RogueSpear2023 · 12-20-2009, 01:54 AM

Well for a Ford 8.8 if it was factroy is has an LSD if he put a locker in it that is possible, the best way tell is get a buddy and do the same thing you would do with an LSD, then if they spin the same way, you would have a locker or and LSD, have him grab the opposite tire if he stops you dead in your tracks it's locker.

brianangst · 12-20-2009, 02:07 AM

sounds like fun, I'm gonna try that in the morning. Thanks for the help roguespear.

Redarcher89 · 12-20-2009, 02:50 AM

if you open the diff case the ring gear should have the ratio stamped on it. At least all Dana gears do.
It will be on the outside edge just below the teeth.

NEWJeeper10 · 12-20-2009, 08:29 AM

redarcher is right. I just had my rear apart last night trying to figure out what was wrong with it and there is numbers stamped on the ring gear. You just divide them and have your gear ratio. For instance mine was 41 11. So 41/11 is 3.73. Therefore i have 3.73 gears. I too had difficulty figuring out what was up with my rear diff. The guy i work with has a jeep and my spider gears are getting wore out so he had his stock ones and we were gunna change them. Well, the pin was too small for my carrier, but when we looked up all the part numbers, they were all the same. When i took it apart last night i saw that it was an LSD. But the clutches are bad on it so if i would spin the one wheel the other would spin the opposite direction so that could be an issue also. Just a thought