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Dana 44 Teraflex Differential Covers

Teraflex Dana 44 HD Differential Covers

Part #: 3990650

Time for covers again on the differntials. I have scrapped my differential cover across a few rocks, but luckily I haven't managed to crush, dent or peal the lip back on any of them yet. So having a little insurance for when it does happen is well worth it. There are many good heavy duty covers out there on the market, so personal preference and cool factor is always good. Heck I like the Poison Spyder covers just because they have the spyder on them, and the ARB's just because they have a dipstick. I like the Teraflex covers because they have the two fill hole levels. What it really boiled down to was a sale. I was able to pick up 2 Teraflex Dana 44 covers for the price of one with free shipping... woohoo..

Additional Parts:
4 Quarts - Synthetic SAE 75W-140 GL5 (Total)
Permatex RTV
Brake Cleaner
Dana 44 Lubelockers (optional)

Tools Needed:
1/2" Socket
14mm Allen wrench or T-14 Hex Head Socket
3/8" Ratchet
Extension
Torque Wrench
Rubber Mallet or Dead Blow Hammer
Gasket Scraper
Bottle Pump
Safety glasses
Scribe
Oil pan

 

Here is what comes in the box.  The Teraflex covers come with new bolts and plugs for the fill holes. Nice thing is that they are already painted, so you don't have to worry about that part.
 
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:
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.


Lovely!

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. 
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.
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. 
On the Rubicon models, you will need to remove the bracket that holds the lines going to the front and rear lockers.
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 and will use it for years to come.
4. Remove the top bolt and cover.  Lay the cover and bolts aside.
5. Drape a clean rag over your differential gears so that you don’t get gasket material into the gears.

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

Be careful around the bolt holes since there may be some raised edges.  This will damage the blade on your scrapper. 
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.
8. This is a good time to take a look at your gears and inside of the differential.
 
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. Test fit the cover and bolts.  This way you don't have any surprises when you actually put it on.
3. Apply a continuous 1/4" bead of RTV along the mating surface of the Teraflex 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. 
3a. If you are using the Lubelockers, install them vice using the RTV.
4. Place a couple of the new supplied 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. 

4a. I have a set of alignment pins that screw into the differential and make it really easy to install the covers.

Differential Cover Alignment Pins

5. 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 torqued is important.  You should be able to do this in 5 to 10 minutes. 
The Rubicon Models have a bracket to hold the harness for the rear lockers that mounts to the cover of the rear differential. The Teraflex covers do not allow you to remount this bracket using both bolts, so your choice is to leave it off, or just use one of the bolts to hold the bracket.
6. On the Dana 44’s.  Reinstall the drain plug in the differential. Install the lower fill plug on the TeraFlex covers. You will need an ratchet, extension and a 14mm allen wrench/socket.
7. 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
8. 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 hem from just about any auto parts store.  Fill your differential with oil.  The Teraflex covers will hold a little bit more oil than the stock covers.  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.  I usually go by where the level was in the beginning.  The people I know at the dealership fill it to the 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.
9. Then, using a 14mm Allen wrench, install the new fill bolt provided with the Teraflex differential cover.  Tighten this bolt to 25 ft. lbs. of torque.
Comparison Shots


Rear Covers


Front Covers

10. And the final product.
Rear Cover

Front Cover

 

Teraflex, Inc
5241 S. Commerce Dr.
Murray, UT 84107

801-288-2585

www.Teraflex.biz


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

This page last updated: 12-Sep-2017

Content and Design © 2002-present WanderingTrail,  Ronald 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. While I have spent many years working on mechanical systems, I am not an expert, nor do I pretend to be one. I hope these write ups have been useful to you.
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