Differential service

kendall · **Posted:** Wed Dec 28, 2005 9:27 pm

My dealer recommended differential service at 12,000 miles at a cost of about $110. Do I need to have this done now, or can I wait? Is it a service I can get done for less elsewhere? If I do that, will it void the warranty?

Thanks!

Jeepjeepster · **Posted:** Wed Dec 28, 2005 9:37 pm

I did front and rear for less than $50 myself. If you dont tow, i wouldnt worry about it until around 24k. I tow a boat so i wanted syn in them. I wont do it again until 30k.

kendall · **Posted:** Wed Dec 28, 2005 9:43 pm

So differential service is just replacing the fluid in the differentials? I don't have a garage (live in an apt) so doing it myself is probably out of the question. Do you think I could get it done cheaper at a shop without voiding any warranties?

Taz · **Posted:** Wed Dec 28, 2005 9:59 pm

Mopars use synthetic lube and an additive for the locker if you have one for the diffs. If you take it somewhere else make sure that they use a lube that meets the Mopar specs, otherwise the warranty could be voided.

ManicMechanicJoe · **Posted:** Wed Dec 28, 2005 10:38 pm

Taz wrote:

Mopars use synthetic lube and an additive for the locker if you have one for the diffs. If you take it somewhere else make sure that they use a lube that meets the Mopar specs, otherwise the warranty could be voided.

Sorry to nitpick but I gots too. DC does not put a locker in our friend the Liberty. It is a limited slip and there is a world of difference. Most if not all lockers do not require an additive in the gear oil. A limited slip requires what is known as a friction modifier. If you don't put this friction modifier in the gear oil, your pour little limited slip clutches will wear out and you're back to an open diff years before you should be (all clutch type limited slips wear out over time). Certain Lockers will also wear out over time (I believe the Gov-Lock or Eaton G80 is one of them). Since we can have a ton of suspension travel like the folks running solid axles, a well thought out differential is our best friend. A locker can make up for suspension travel.

Taz · **Posted:** Wed Dec 28, 2005 11:10 pm

You are correct, I mistyped, the Liberty has limited slip (Trac-Lok). It does need the additive. One interesting note it is not listed as an option on the 2006.

Jeepjeepster · **Posted:** Wed Dec 28, 2005 11:23 pm

yes, thats all they do is replace the oil. I would never play over $100 for just the rear axle. I would not do it if it were me. The tranny doesnt need it till 30k and im sure the axle could wait till 24k. If your not hard on it and dont have a Limited Slip or tow, you should be fine.

Edit: It will not void your warrenty. Keep all receipts!!

2003KJ · **Posted:** Thu Dec 29, 2005 12:30 am

I was quoted about $75 per axle from my dealer....after I laughed and hung up the phone I decided I would do it myself.

I don't do any towing, hardly any offroading, and I was a bit surprised to see how dirty the fluid looked, especially in the rear, when I changed it a few weeks ago....right at 28K.

Got to be, by far, one of the easiest things I've ever done. If you've got 4 jack stands that are tall enough and strong enough to support the weight of the Jeep, and a decent floor jack to get it up high enough to get the jacks under, and a fairly big bucket to dump all the old stuff in, you're pretty much set. Just make sure to pick up some RTV sealer from where ever you go by the Fluid from as the rear diff. cover is held on by RTV, and not a gasket.

I started with the rear, since it takes the longest. MAKE SURE YOU HAVE THE BUCKET UNDER THE DIFF. FIRST!!! Once you do, loosen the bolts from bottom to top, and wait and see if the cover begins to break loose. Mine was on there pretty darn tight, so nothing happened. If thats your case, go ahead and pull all the bolts off. You might have to do what i did and get a really long flathead screw driver and a hammer. Use the hammer to pound the tip of the screwdriver into the RTV you'll see on the side, just like a chisel. This should begin to break it free. Then work your way around doing the same thing untill you can get a good section off and let the majority come out. Once most is out, you can go ahead and pull the cover off the rest of the way with your hands. Now comes the fun part, waiting for it to all drip out. I gave mine probably a good hour to drip. so while its dripping, go play with the kids, the dogs, grab a beer or two, or whatever to kill the time. Then take a paper towel or something and scoop out the little remaining old fluid from the bottom of the diff., and THEN take a putty knife or something, and scrape off ALL the old RTV from the diff. cover and the diff. itself....don't forget to wipe out the diff cover, and pop the fill plug out of the diff cover while you got it off!

Spread some of the RTV on the cover, pop it back on the same way it was when you took it off, and then hand tighten all the bolts. If you have a torque wrench, or access to one for a few minutes.....run back over them and torque them down....i can't remember what i set mine at off the top of my head right now....don't go crazy with it obviously. Give the RTV a few minutes to set and dry a bit, and then you can fill the stuff up. You should be able to leave the stuff in the bottle and pour it in directly from the bottle with out making a mess, just cut off a good chunk of the tip of the bottle. I just filled it up till it ran out, and then let it drip a bit till it was even, and popped the fill plug back on. Wipe it down with a paper towel and move on to the front.

The front is extremely easy. Chrysler was smart and included a separate Drain and Fill plug. Put your bucket under the bottom of the full plug, and unscrew the drain plug. Shouldn't take nearly as long to drip drain as the rear...I think i let mine drip about 20 minutes and it was good to go. Put the plug back on, and take off the fill plug. Fill er up untill it starts running back out, and let it even out before you put the plug back in. Wipe it clean, and you're done.

All of this can be done for rooughly $40 depending on what brand you choose for fluid. I stuck with what the book recommended for fluid. 75W90 (standard gear oil) in the rear, and I dont recall at the moment what weight goes in the front, but the front does require synthetic. All this takes only a couple hours....depending on how much Murphy's law kicks in. Don't be afraid to do it yourself...I know i was a bit leary at first, but I'm glad I did. Learn alot in the process, plus you get it done alot cheaper, and with the satisfaction that it was done, and done right.

To find the fluid type for the front, it's listed in your OWNERS MANUAL (the one that came with the Jeep)

LibertyCRD · **Posted:** Thu Dec 29, 2005 8:36 am

I'd just like to point out a few things.

If your dealer says they will do the diffs for $75 bucks each...JUMP ON THAT DEAL. The proper fluid for these differentials costs $15-$20 per quart, and you need almost 3 quarts. Plus it's at least 1 hour labor per diff. You do the math. $75 per diff. would be a heck of a steal. My dealer quoted me over $200 for both diffs. on my wife's KJ so I did it myself.

Also, when I changed my wife's diff fluid at 15,000 miles, the rear fluid was NASTY and had even built up some sludge in the bottom of the housing around the magnet. Keep in mind her KJ never tows or off-roads...it's a soccer mom vehicle. So NO I would not wait until 25 or 30k to change the diff. fluids. I'd definitely follow the owner's manual recommendation on this!

2003KJ · **Posted:** Thu Dec 29, 2005 9:41 am

maybe I should wake up before i type a long post like that. I ment to say that it was $75 labor per axle, plus the cost of the fluids and the RTV brought it to right around $300-$350....sorry for the confusion....coffee rush had worn off when I typed that last night.

Plus, I happened to find the fluid on sale at NAPA, and, I'm good friends with the main parts guy down there, so he hooks me up often

LibertyCRD · **Posted:** Thu Dec 29, 2005 9:55 am

Yeah that sounds about right. Now that I think of it...I believe our quote at the dealer was actually higher as well.

My uncle owns our NAPA store here, and he still tried to get me for $17 per quart on the fluid! LOL! :shock:

I ended up putting regular "dino" fluid back in my wife's. It was $3.50/quart and is the proper weight. Should be fine for her Jeep. That synthetic fluid is outrageous.

Differential service

Who is online