Changing Rear Differential FLuid

[The Bandit]

I have a couple questions before I tackle this next job. I have a 03' Jeep Liberty 3.7L 4x4 Sport I just purchased. It has the factory tow package, which I am not too sure what this means. (feel free to inform me) I want to change the differential oils and tranfer and ****** oils. For the rear pumpkin, I know I need to change it to SAE 75W-140 Synthetic Gear Lube as the manual suggests for towing, as I tow a 2700 pound Glastron for good times. It says Models equipped with Trac-Lokrequire a friction modifer. Now first of all I don't know if I have this Trac-Lok and to be honest I not well researched on it either. If anyone knows, inform me, I can find this out from a dealer if I give them the vin I assume? Also I assume this is a Limited Slip Rear Diff, so should I be putting in a Limited Slip Differential Additive as well? I plan on using Amsoil products and I think the additive is added with the Lube. I want to do this right and any info is greatly appreciated. Thanks

 

[oddball]

First - Welcome to the forum and congrats on your new KJ.

As for the tow package, I assume you have a rear hitch & wire harness. I think (not positive) you may also have a clutch mechanical fan (instead of or in addition to the basic electric fan)? Someone with more knowledge and or a tow package will hopefully provide factual details on this.

As for the Trac-Lok - There should be a tag on the rear diff (or axle) if you have the limited slip. If there isn't a tag, that doesn't mean you don't have it either. It may have been removed? You can request (email or phone) a free build sheet from Jeep/Chrysler and that will tell you everything about your Libby.

Wise choice on Amsoil. However; You will need to order "Slip-Lock Differential Additive" in addition to the 75W140 lube. (p/n ADABA 4oz bottle).

 

[kb0nly]

I'm in the same boat here, 03' KJ and working on changing all the fluids before winter just to be ready with everything.

I used the sticky on here to request a build sheet online, but if you have a dealer nearby i would do it that route its less painful as you can do it right there at the counter. The problem is i think the build sheet says i have a 42RLE trans when its actually the 45RFE. The 45REF pan gasket has 15 holes, the 42RLE has 13 holes, and mine has 15 bolts.. So the build sheet is wrong there but anyway... As for the rear end all it says is 8.25 rear, it doesn't say anything about the options in the rear end, limited slip, etc..

4-Spd. Automatic 42RLE Transmission
Lock-Up Torque Converter
Command-Trac Part Time 4WD System
Dana 30/186MM Front Axle
3.73 Axle Ratio
Corporate 8.25 Rear Axle
3.7L V6 Engine

 

[drawnon]

hhhmmmm... i changed my 03 sport rear diff fluid a couple of months ago. i indeed had a tag on the bottom bolt of the diff. but i could have sworn it was stamped 373. i thought that was just the gear ratio. i just filled it back up with auto zones house brand name gear oil. i think the name brand was coastal. it was the correct weight ( i left the bottels at my dads house, so i cant check ).
did i screw up? im on the highway everyday. i dont tow much, and when i do its a small jon/bass boat. maybe 400 total lbs at the most.

 

[Mangate]

There's a green or yellow sticker on the outboard end of the left axle tube which identifies wether the diff is LSD. You can see it just crawling under the rear end. Do a search on here, the details are there.
Of course the sticker may have fallen off by now, mine is still there on a 2002.

 

[Chris9296]

chances are if you have a corp. 8.25 rear end, then you more than likely don.t hvae a trac lock rear end. You can always call the dealer and have them run the vin and that should tell you. Worst case scenario, if you have a trac-lock and do not put in the additive you will know fairly quickly. Main symptom is when you turn a corner you will notice noises and possible vibration. The additive is a friction modifier that helps the clutches in the rear end to mate to eachother better. Hvae a little experixnce with this. When I worked at a ford dealer, another shop in town did the rear end fluid on a police cruiser and did not add the friction modifier. The officers that driove that cruiser complained of those symptoms. The dealer ended up removing the fluid and put in new flid with the modifier. Now if you were to make that mistake, you could very easily remove some fluid with a suction gun and add the additive.

 

[kb0nly]

chances are if you have a corp. 8.25 rear end, then you more than likely don.t hvae a trac lock rear end. You can always call the dealer and have them run the vin and that should tell you. Worst case scenario, if you have a trac-lock and do not put in the additive you will know fairly quickly. Main symptom is when you turn a corner you will notice noises and possible vibration. The additive is a friction modifier that helps the clutches in the rear end to mate to eachother better. Hvae a little experixnce with this. When I worked at a ford dealer, another shop in town did the rear end fluid on a police cruiser and did not add the friction modifier. The officers that driove that cruiser complained of those symptoms. The dealer ended up removing the fluid and put in new flid with the modifier. Now if you were to make that mistake, you could very easily remove some fluid with a suction gun and add the additive.

I got the full build sheet from Jeep with my VIN, and no mention of the rear end other than 3.73 gears and Chrysler Corp 8.25.

The thing is, you have to pull the cover off the rear diff to change the fluid, so while i have the cover off i can see whats in there anyway, and if need be run over to the parts store and get the different fluid, etc..

I ordered a diff cover gasket and plan on doing the transfer case, fresh ATF+4, the front and rear diffs, fresh 75W140, and eventually the trans as well. Only 48k on it and it was last serviced at 30k, so i will probably wait until 60k and do the trans, fluid still looks clean.

 

[Mangate]

chances are if you have a corp. 8.25 rear end, then you more than likely don.t hvae a trac lock rear end. You can always call the dealer and have them run the vin and that should tell you. Worst case scenario, if you have a trac-lock and do not put in the additive you will know fairly quickly. Main symptom is when you turn a corner you will notice noises and possible vibration. The additive is a friction modifier that helps the clutches in the rear end to mate to eachother better. Hvae a little experixnce with this. When I worked at a ford dealer, another shop in town did the rear end fluid on a police cruiser and did not add the friction modifier. The officers that driove that cruiser complained of those symptoms. The dealer ended up removing the fluid and put in new flid with the modifier. Now if you were to make that mistake, you could very easily remove some fluid with a suction gun and add the additive.

Both of mine have the corp 8.25, and both are trac lock.

 

[kb0nly]

Did you pull your build sheet? Just wondering if it said anything on there about it, mine didn't.

I will look for that sticker you mentioned also, i did a search on here and couldn't find the info, what does the green and yellow stickers stand for?

 

[rjcapp]

The green label on my rear axle says
52114030AA
8.25 KJ
3.73 OPEN-CASE

Do I have trac lok?



What if you have trac lok and didn't know it, changed the rear diff oil, did not add the LSD additive, and drove it for 500 miles? That might be me.

What if you just added the additive either way just to be safe?

 

[Dave]

The green lable on my rear axle says
52114030AA
8.25 KJ
3.73 OPEN-CASE




What if you have trac lock and didnt know it, changed the rear diff oil, did not add the LSD additive, and drove it for 500 miles? That might be me.

What if you just added the additive either way just to be safe?

Adding the friction modifier if you don't have trac-lock won't hurt anything. It is just not necissary. The axle tag will tell you if you have it and you are under there anyway so you can look at the tag. It should be on the drivers side axle near the wheel end. When you pull the diff cover you will know for sure.

Dave

 

[Mangate]

Did you pull your build sheet? Just wondering if it said anything on there about it, mine didn't.

I will look for that sticker you mentioned also, i did a search on here and couldn't find the info, what does the green and yellow stickers stand for?

Took me a few searches to find it again, but here it is.

http://www.jeepkj.com/forum/showthread.php?t=31536&highlight=trac-lok

 

[JJsKJ]

Heres a visual:

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[The Bandit]

I figure I have Limited Slip, and Ill be off to the dealer soon. I bought this vehicle from people who had it for a year, and they had no clue what the prior maintainence was, and there was no paperwork as to maintanence done to the vehicle bu the previous owner. But I do have the shimmy when turning corners, which to me precipitated the need to change the dif oil. I gotta think the dif oil was changed at some point and the anti-loc additive was not used. Off to the dealer I go.

 

[lynxer]

I have trac lok do I put the friction modifier in the front diff too?

 

[RageOfFury]

I have trac lok do I put the friction modifier in the front diff too?

NO! Just in the rear

 

[lynxer]

NO! Just in the rear

That is what I thought, but it doesnt specifically say anywhere so I thought I would ask. I am doing my Diffs. today after work.

 

[karter]

Pull the rear diff. cover . If you see spider gears in the ring gear carrier it's an open diff. ,not a limited slip diff . Also the rear cover uses black hi temp RTV for the seal . Clean the diff cover and the housing sealing surface , put a bead of RTV on the cover and let it sit for 10 minutes or so and reinstall the cover . Rear diff will hold about 2 qts. of your favorite gear lube .

 

[ptsb5a]

Correct me if I'm wrong, but here's an old hot rodder scrap yard trick to find if the diff is open or limited slip (posi). Get the rear end of your KJ off of the ground, put the T-case in neutral and turn one of the wheels by hand. If both wheels turn in the same direction it's limited slip. If one wheel rotates opposite of the other, the rear end has an open diff. Or, have one of your buddies hold one wheel while you turn the other. If the wheel turns without a whole lot of grunting from the other side it's open. If your buddy has to work hard to keep the wheel from turning in the same direction as yours and you find it difficult to turn, it's limited slip.

 

[tjkj2002]

Pull the rear diff. cover . If you see spider gears in the ring gear carrier it's an open diff. ,not a limited slip diff .

Not correct,below is a pic of the Trac Lok carrier...............

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Below is a pic of a open carrier............

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Kinda look the same don't they?

Correct me if I'm wrong, but here's an old hot rodder scrap yard trick to find if the diff is open or limited slip (posi). Get the rear end of your KJ off of the ground, put the T-case in neutral and turn one of the wheels by hand. If both wheels turn in the same direction it's limited slip. If one wheel rotates opposite of the other, the rear end has an open diff. Or, have one of your buddies hold one wheel while you turn the other. If the wheel turns without a whole lot of grunting from the other side it's open. If your buddy has to work hard to keep the wheel from turning in the same direction as yours and you find it difficult to turn, it's limited slip.

Not 100% true anymore and also depends on how worn the clutches are in most LSD's also.