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Jeep Differential Oil Change

Changing your Differential Fluid

Part #:

Now while these pictures are specific to the Dana 44, the other axles are almost the same with the exception of the Dana 44’s Drain plug.  Changing your differential oil is something all of us can do, it’s fairly simple, doesn't take a long time, and is cheaper than taking it down to the local oil change place and having them stick a suction tube in your differential and calling it good.  I have seen to many screwed up differentials courtesy of these locations.

Jeep recommends changing your differential fluids every 24,000 miles if you follow “Schedule A” or 12,000 miles if you follow, “Schedule B” in the owner’s manual.  It is also a good ideal to change the fluids if you have been in any deep-water crossings or been stuck in a stream where your axles spent some time under water.  Normally just crossing a stream or water would not require you to change your axle fluids, but as the axles get older, the seals start to wear out.  The sudden cooling of the axle from the water can suck water in through a seal. 

Additional Parts:
4 Quarts - Synthetic SAE 75W-140 GL5 (Total)
Permatex RTV
Brake Cleaner

Tools Needed:
1/2" Socket
3/8" Ratchet
Extension
Torque Wrench
Rubber Mallet or Dead Blow Hammer
Gasket Scraper
Bottle Pump
Safety glasses
Scribe
Oil pan

 

Preparation:

You may need to lift the vehicle from the frame to gain better access to the differential cover.  Place an oil pan and some rags or newspapers under the differential.
 
Removing the old cover: Rear Differential Cover
Rear Cover
Front Differential Cover
Front Cover
1.  Drain the fluid from the differential.  Remove the fill plug from the cover.  On the Dana 44’s this is a steel plug front and rear, some of the other Dana’s have rubber plugs.  Drain the fluid.  Some plugs may have magnets installed so you will need to clean off the accumulated metals and sludge.  You should normally have some buildup on the plugs especially if this is your time removing the plugs. Cover fill plug Removing cover fill plug
I have had the Jeep in some deep water pervious to this oil change, hence the reason why. This is what I found when I drained out the oil. It was this nasty smelling, mucky stuff. I definately had gotten a little muddy water in here, luckily not to much. Nasty oil draining out
Lovely! Not the color it should be.
1a. On the Dana 44’s there is a drain plug on the differential.  Just remove the drain plug with a 3/8” ratchet.  You may need a short extension for some ratchets to get to the plug.  Dana 44 Drain plug Removing Dana 44 drain plug
1b. The Dana 44's have a magnet on the drain plug to catch any metallic particles. You will need to clean this off. Mine had a bunch on there since this was the first oil change. Now if you just want to change the oil in the Dana 44's, then you can move on to just reinstalling the drain plug and refilling, but it's always good to pull the cover and take a look at the gears and inside. Comparing plugs Cleaning plugs off
2. Remove the bolts holding the cover on with a ratchet and 1/2” socket, leaving the top bolt partially installed.  Be careful you do not drop anything in the pan of oil that is sitting underneath the axle.  Removing rear cover Leaving a bolt in
2a. On the Rubicon models, you will need to remove the bracket that holds the lines going to the front and rear lockers. Removing bracket Another bracket to remove
3. Once all of the oil is drained, or to drain the oil, use either the rubber mallet or dead blow hammer to knock the cover loose.  The dead blow works the best.  The top bolt that you left installed will catch the cover. 
Note: if you decide to remove all the bolts and then hit the cover with a hammer to knock it free, the cover will immediately hurl itself into the pan of oil and approximate the meteor that hit the ocean in Deep Impact.  Should I mention that the significant other will probably witness this event.
Tapping the cover off
4. Remove the top bolt and cover.  Lay the cover and bolts aside. Cover free, draining oil Cover removed
5. Drape a clean rag over your differential gears so that you don’t get gasket material into the gears. Covering the differential

6. Use the gasket scrapper to gently scrap any adhesive off the differential mating surface.
Note: Rag was removed for picture purpose.

Scraping gasket material off Differential Still scraping differntail gasket material
Be careful around the bolt holes since there may be some raised edges.  This will damage the blade on your scrapper.  Finishing off the differntial
7. Use the scribe to remove any adhesive from the bolt holes.  Old adhesive in the bolt holes will affect your torque when you bolt the cover back on and may cause the cover to leak. Cleaning out the bolt holes

8. Scrape all of the gasket material off the differential cover that you removed.

Cleaning off the cover gasket material Scraping the cover gasket material
9. Clean the gasket material from the threads of the bolts that you removed.  Having gasket material on these bolts will affect your torque setting when you reassemble the cover.
10. This is a good time to take a look at your gears and inside of the differential.
Here is a quick comparison between the two covers. You can see that the front covers fill plug is lower than the rears plug. Front and rear Dana 44 cover comparison
 
Installation:

1. Use the brake cleaner and some lint free cloths (good paper towels) to clean the mating surfaces on the cover and housing.  Remove the rag that you covered the differential with and clean out any debris that got past it. 
Note: Do not spray brake cleaner on any plastic or rubber parts.  The brake cleaner will deteriorate these and can lead to failure.

2. Apply a continuous 1/4" bead of RTV along the mating surface of the differential cover.  I run the bead down the center of the mating surface and make a loop around each bolt hole.  This will give a better seal in the bolt area.  Applying sealant to cover bolt holes Sealant on entire cover
3. Place a couple of the bolts on the ground right under the cover.  I carefully slid 1 bolt through the top of the cover.  This will help you line up the cover and get a bolt started without having the cover slide around.  Lift the cover up and carefully place it onto your differential making sure not to move it around too much.  Once you have the cover lined up, install a bottom bolt to help hold it in position.  Reinstalling cover

4. Install the rest of the bolts that come with the kit.  Run all the bolts down until they are just finger tight, or snug.  Then torque them down using a crisscross pattern to 25-30 ft. lbs. torque.  Do not over torque these bolts; you do not want to try to drill out a hardened bolt from a differential.  The RTV is curing, so getting the cover down and torque is important.  You should be able to do this in 5 to 10 minutes. 

5. On the Dana 44’s.  Reinstall the drain plug in the differential.

Reinstalling Dana 44 drain plug

6. Take a break or go work on the other differential if you are doing both of them.  I usually let the RTV cure for a little while before I dump oil in on it.  I leave my bottles of oil back by the differential just as a reminder.

7. Fill up your differential with the appropriate gear oil.  The Dana 44’s on the Rubicon’s use 75w-140 gear oil.  Some of the other axles have Trac-Loc that requires a special friction modifier to work properly.  Most synthetic gear oils already have it mixed in, or you can pick up the little bottles at the Jeep dealership.  Now actually filling the differentials is a pain if you do not have a cheap bottle pump.  I picked one up at pep boys, but you should be able to get them from just about any auto parts store.  Fill your differential with oil.  I have seen, been told a few different ways to fill your differentials, one being fill to the edge of the fill hole, another fill to ½” below the fill hole, and even another that said put in what the factory said to put in.  Strange how that amount does not come out of the differential in the first place.  The owners manual says to fill it to the bottom edge of the fill hole.   Do not try to cram more oil in the differential this will only cause problems with gear oil being pumped out of the axle breather tube. It is best check your owners manual for the amount of oil used in the differentials.

Siphon pump
8. Then, using a 3/8" ratchet, install the fill plug in the Dana 44 cover, or reinsert the rubber plug, dependent. Reinstall cover plug


  N-m Ft. Lbs.  
Differential cover bolts   25-30  
Dana 44 Drain plug   25  

This page last updated: 04-Apr-2012

Content and Design © 2002-present WanderingTrail,  Ron Seegert
Common Sense and Safety should always be observed when working on your vehicle or doing modifications. Jackstands, wheel blocks, disconnecting the battery are a few of the basic safety precautions that should be used and may not be mentioned in the write ups on this site. You are responsible for your own installation, these write ups are a helpful guideline and should not be taken as an official installation instruction. My write up may be different from the kits currently out there, so alwasy double check the manufacturers installation instructions when installing anything. I try to keep the site up to date with changes that have occured as I discover them, but may not have the latest unless someone lets me know. If you feel that an install is above your capabilities after reading my write ups, I recommend getting together with a club and getting some help. Only a few times have I needed to employe some actual help from a shop to get something done. Usually welding or A/C work.
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