MAINTENANCE: Jeep JK Wrangler
Differential Fluid Service Write-Up

50 Comments

1. it’s just not necessary. if it’s in there, no harm will be done.

2. Hey! LOVE this place! I had to get the seal replaced on my rear diff which was covered by the warranty, fluid was not… anyhow they wanted to change to front for $129. I was under it and saw how they were changing the back…I am not dumb and I love tools. Sooo, I want to change the front myself. My questions: Do I really need to take the cover off? What do I buy for a seal if so? And can I use the recommended 80/90 diff fluid from the local store? If I do not take the cover off I simply drain and replace? No flushing? I am full of questions I know… thanks for this site though I love it!

3. if you have a JK, no, you do not need to take the cover off just to change the oil. there is a drain plug on the bottom of your differential just like this write-up shows.

4. Ok so please anyone..Bought a 2007JK…has 18 inch rims so previous owner did that I guess as an upgrade..I want to clean the diffs and add new oil etc. How do I know if I have a limited slip or not without jacking the rear up? It is an X version and I have heard it can be either? Help! Thanks

5. So as long as you use gear oil like Valvoline 80w-90 that says ok for for hyphoid limited slip you do not need the additive??

6. Working on this now…great instructions! Only thing I would add is that there is a little “nipple” on the top of the Royal Purple…take it off before you go anywhere near your fill hole on the diff! I was going in for a test pour, just to check the angle (my first time doing this) and that little piece fell into the front diff! So I am now doing the complete fluid change on the front! Already did the rear, but am waiting for someone to come give me a ride to store for RTV! D’OH!

7. Went in today for a 9.95 oil change and was told I need to do a fluid change in my differentials. Estimated cost from the dealership: $360.00!!!!

   Thanks to this community and you regulars here, I did the whole job for under a 100.00 bucks with Royal Purple. Not only did I save money, but I did some of my first maintenance my my Jeep. So cool.

   This is an amazing resource. Thanks for those of you who put time into this.

8. Just bought a used ’08 Wrangler Rubicon right at 30K miles – so I was due for all of this. Dealer wanted $240 – mine – less than $90.00. Thanks so much for the clear instructions and pictures. And it’s fun to work under my Jeep for a while. This Forum ROCKS – thanks much!

9. I am replacing both of my diff covers with ARB covers. I have a 2 door JK with a 3 1/2 lift. Two questions:
   1) Will the fuild amounts increase, decrease or stay the same with the ARB covers? They seem to have a larger cavity.
   2) Does the 3 1/2 lift tilt the diff enough that is rotates the diff drain bolt down. Should additional fluid be added?
   Marty

10. it should be about the same and, being that you have an arb cover, all you really need to do is use the dip stick to see where you’re at. all you really need is to have your fluid be a bit above the bottom of your axle tubes. any more than that and you will have over filled your diff and can expect a stinkin mess.

11. Great write up! You’d be surprised how many guys out there don’t know that you even have to change the differential oil. Did mine today and it was a snap. But damn is that oil stinky! Wow!

    Anyway, my question…I put 5.13 gears in and went through the break-in process and changed the oil as required at 500 miles after install. I put in Mobil 1 75W90 synthetic (has the LSD additive). I just read that you guys recommend 75W140 for 5.13s. I’m guessing I’ll be fine, but I want to make sure.
    Thanks!

12. ok followed the write up but i also changed to riddler covers and they don’t have the recess that the factory covers do so i went with the old fashion fill it until its full theory so the front was a little more but the rear took almost 4 quarts! the front was about 2 1/4 of royal purple and since this stuff is like gold I am a little concerned that now i am smelling gear oil on the interstate and am seeing wet spots but nothing coming from the actual covers should i be concerned or will it all blow out the vent? I have a stock jk rubicon unlimited.

13. the old method of filling till it’s full only applies to diff covers with a fill hole at factory height. your fill hole is too high and you way overfilled your diff. regardless of diff cover, you should only put in as much fluid as is recommended by the owners manual or, to a point just a bit above the bottom of your axle tube.

14. Great write up, I got 1 qt in the front and about two in the rear with my rubi 44s. Looks like other people had the same. Thanks for the write up, made it nice and easy to do for the first time.

15. I might have overlooked this answer, but in my vehicle book it calls for 75W-140. Any reason why I can get away with 75W-90? Thanks…

16. Great write up! Dealer wanted to charge me $400 to do this….I did it myself for $90. Quick question though….what is the easiest way to get the oil to the front diff? Made a MESS as the bottles would not find in the gap to the fill hole, and ended up needing to get a small flexible tube, and even then, took FOREVER to fill. Any suggestions?

17. pls, help me if you can. I hear knocking in my back diff,and when I open it and drain the oil I notice one spider gear have a small chip . I just hear this when i backing up never hear when i drive forward. you think is better change this spider gear for safe? thanks for your help..

18. I just pick up valvoline 75-90 it says limited slip on the bottle, I have 07 X will that work? I don’t tow anything

19. Thank you for this forum, great info. I will be trying to change my SD Fluids this weekend very excited. My local dealer wanted to get me for $240.
    I’m glad I don’t need them. Thanks again.

20. my dealer told me to put 70w140 the thing is ther is a big difrence in tempeatur between 90 and 140

21. FWIW… Some previous wranglers also have the drain plug. My ’06 LJ Rubicon does.

22. Thanks Eddie! Did it today. Followed your instructions to a T and it was a piece of cake. Also saved a ton of money. Keep the write ups coming. Thanks again!

23. Thanks,…I managed to complete both front and rear, and I am not a very skilled mechanic. I did run into one issue. In removing the drain plug on the front diff, using a ratchet with 3″ extension, I managed to get the tool wedge between the bracket immediately across from the drain plug,.. and the diff.,it was a very tight fit. The ratchet head I used was not very slim, but I was curious, is a low profile ratchet head the trick, or is there something I was missing. (I eventually had to cut the tool in half with an angle grinder, to dislodge it) I have an ’09 X 2 Dr BTW

24. you can always use a 3″ ratchet extension to make things easier.

25. Hey Eddie – Great write up. I recently talked to the Stealership and as everyone else stated. They wanted about $360 for the Diff oil change. I am going to do this within the next month and just wanted to give a shout out and thanks for all various How-To’s.

    Evo35

26. I have a ’10 JKU sport W/O the tow package so the gears should be the 3.73 gears. My question is this, I live in Germany (stationed with the Army here) and I am ready to change the Diff fluid, Is there a problem with using the Royal Purple 75W-140? The Army store does not have the 75W-90 and they have no idea when it will come in. I could get the right stuff from the dealership here in Germany, but I will end up paying about $45 qt as compared to the $18 per qt from the Army store. Any ideas on this? Will it hurt it to run the 140? What about just running the 140 in the rear? The reason I want to change is I am right around 40k miles and am feeling a bit of roughness in the drive line and want to also inspect the gears. Any help with this would be appriciated. Thanks.

27. I know this was written a while ago, so I hope that someone can answer my question…I have a ’08 Rubicon (4″ lift, 35’s) I had to change out the rear differential seal yesterday(THANKS FOR THE DIRECTIONS!). I bought 4qts of AMSOIL 75w-140. I used just under 2qts for the rear and since I have 2qt left over I was thinking about changing the front fluid. QUESTION>>>Manual says to use 75w-90 for front, what are your thoughts on using the 75w-140 that i have on hand?

28. it won’t be a problem

29. Eddie,

    I have a 2012 JKUR. The maintenance schedule in the owners manual only has one schedule (no plan B) which seems odd and it recommends the first diff oil change at 24000. Do you know if they have extended this from 18000 or am I missing something. Thanks for all the great write-ups. Quite an collection of good stuff.

    Eddie (Great name by the way) Lol

30. Easiest $ ever saved. Thanks!!

    I have a stock 2011 JK Rubi. Used Castrol Syntrax 75w90. I got a bit over 1qt up front and right around 2 in the back.

    I am typically in 2wd, as this is the daily driver – 100% city. I’ll do some minor off road soon.

    Is the Castrol blend above OK to leave, or do I need to drain/replace with something better? Do those levels sound about right?? Both front and back did start oozing out – that’s when I plugged them both and called it done. I’m not the most mechanic, first time diff job, and always 2nd guess myself on new stuff like this. I just want to be safer than sorry here and avoid a costly repair.

    Thanks again for this right up!

31. Hi, I have a Rubicon and put Teraflex diff covers on, I believe the theory is wanting to have fluid half way up the axle tubes, that’s where the drain plug is located on the covers, my front axle took 2 quarts until mid axle tube, the rear took about 3.

    Is this okay having this much in it?

32. You have too much fluid in. You only want the fluid to sit at the base of the axle tubes. Anymore than that will cause the fluid to get pumped out the vent tube or out the seals.

33. I changed my rear with 2qt of royal purple I sweat by the stuff

34. I have not read the write-up just the comments.I will when the job is complete
    awesome!!! answered all my questions
    off to fix my busted drive axle u-joint.
    Royal Purple it is
    thanks

35. Everyone seems to be saying that they are doing the diff fluid change for $80 to $90. That must mean that they are buying 3 to 4 quarts of SYNTHETIC gear oil. I have an 07 Rubi (2 dr) and I am planning to do the third diff fluid change myself (first two changes were completed by the dealer, kiss that money good bye). Is it not okay to use regular 80W90 gear oil (for about $30, instead of $90). I will not be doing any towing. I am no mechanic, so forgive my ignorance.

36. I have a 2011 Jeep Sport Wrangler unlimited. I was going to change the rear diff. fluid. I was wondering if I should also be changing the front. Also, what fluid is the best for the cold weather or doesn’t it matter? I live in mid-state NY.
    Also, I was told that I needed some sealant for the cover once I take it off. What would be best to use?

37. It’s a good idea to do both but, if you can only do one, the rear is the one that will need it more. For cold weather and on a diff running factory gears, I would recommend a lighter 75W90 or there about. You will need RTV to seal it up. Click on the link to see the full write-up.

38. Just be careful not to overfill. The dealership changed my fluids before I bought my Jeep used. My Jeep has an aftermarket diff cover with the fill hole much higher. They filled the oil to the top and it blew it out the vent tube and blew out one axle seal which now constantly leaks and needs replaced. Do not overfill or you will blow out axle seals.

39. I have a 12 jk sport will it be a problem to use royal purple with the additive in my dif

40. Your Royal Purple will already have the additive in it.

41. 2014 JKU Rubicon – just upgraded to 5:13 gears. Just passed 500 mile break in. I have the Teraflex diff covers. What diff fluid should be used and what’s the easiest way to get fluid in front diff. Do I need a pump?

42. Just wrapped up the oil change on the rear Dana 44. I used Valvoline 80W90 for Hypoid differentials. However, had already added the LSD additive as well. Will that cause problems. Do I need to flush and redo?

43. You should be okay.

44. Thanks. One more unrelated question. I have a Dana 44 as the front differential (Rubicon 2008). If the rear differential (Dana 44) requires an additive, theoretically shouldnt the front one too. The manual doesn’t state this explicitly, but couldn’t understand the reasoning behind not adding it to the front as well. Can you help me understand this.

45. You only need friction modifier IF you have a limited slip differential. Lockers do not. Regardless, pretty much ALL synthetic gear oils have friction modifier in them.

46. I am replacing my diff covers with ARB. I have lifted my Jeep 3.5″ and clocked the axles for the correct pinion angle. I’m sure that this changes the fill hole check, and I am wondering how much fluid to put in. The new Diff covers have a dipstick, but it needs to be marked for my application. Any recommendations?

47. 12 Rubi with 5:38 75W140?

48. You want to fill your diff with the same recommended amount as outlined by the FSM. If you want to use your dip stick, you just want to add as much fluid as is needed to get it to the base of your axle tubes.

49. i have 2013 wrangler sport 2 door jeep i want to use redline 75 w 90 manual says 80w90 and with the redline i want to use redline friction additive will i be ok with 75w90 and with friction additive will my jeep diffs be ok. also 5 w 20 synthetic oil kendall is that a good oil , the redline diff fluid is also synthetic. than you…

50. sir,i own a 2013 jeep wrangler sport 2 door,can i use 75w90 gear oil instead of 80w90 jeep book says to use 80w90 is it a big difference will it be ok with 75w90 i want to use redline and the friction mod. also what is best tranny fluid atf+4 redline or havoline and is kendall synthetic 5w20 a good oil for engine. thank you us navy just ret. i appreciate your knowlege and help thank you sir.