Differential oil change

[CarbonSteel]

Read this whole thread and I feel *mostly* confident, but there's a lot of opinions and little data.

I have a '21 Sahara with LSD + tow package. It's my daily driver, and I get it out for light wheeling maybe once/quarter (which sucks, but that's another topic). Don't really tow (got the package for the aux switches really).

Just hit 20K miles.

Watched a video on how to do it - seems easy enough. Will make sure I have yellow teflon tape and 2qts of fluid, but which fluid?

90 - mostly recommended, listed in the service manual?
140 - better protection cause it's thicker, but not entirely necessary. Might drop my MPG slightly.

Leaning toward the Valvoline flex fill 140 for both front/rear. Royal Purple is ~$5/qt more - worth it for my usage?

I would go with Valvoline 75W-140. I run it and would rather have the extra protection versus 75W-90.

Your right foot, a headwind, or a hill will have more of an impact on MPG than an increase in viscosity ever will.

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[Rhinebeck01]

@rcadden

I used to use 75-90 for the front and 75-140 in the rear .... but these days I use 75-140 in both front and rear.

If you do your homework, you will learn 75-140 in both front and rear, is a good / better way to go.

FLEXFill pouches make the deed oh so easy!
I encourage you to order a case of this:
https://www.amazon.com/Valvoline-Fl...bc-83cb-a0bef0f821b5&pd_rd_i=B08KB5LTJM&psc=1

 

[BDinTX]

@Rhinebeck01 can you expand on this? Curious what changed your mind. You can PM me if you don't want to start an oil holy war.

"I used to use 75-90 for the front and 75-140 in the rear .... but these days I use 75-140 in both front and rear.

If you do your homework, you will learn 75-140 in both front and rear, is a good / better way to go. "

I still have some 75w-90 on hand that I'd rather not toss out. : )

 

[CarbonSteel]

PS...Dana recommends 75W-140 in both axles, it is FCA that has deviated by recommending 75W-90.

Front - https://d3qx1uccksbb2n.cloudfront.net/docs/SPECSHEET-JL-FRONT-UD44A-42019.pdf

Rear - https://d3qx1uccksbb2n.cloudfront.net/docs/SPECSHEET-JL-REAR-UD44A-D44A-42019.pdf

 

[CarbonSteel]

@Rhinebeck01 can you expand on this? Curious what changed your mind. You can PM me if you don't want to start an oil holy war.

"I used to use 75-90 for the front and 75-140 in the rear .... but these days I use 75-140 in both front and rear.

If you do your homework, you will learn 75-140 in both front and rear, is a good / better way to go. "

I still have some 75w-90 on hand that I'd rather not toss out. : )

Nothing wrong with using 75W-90, you just have more protection with 75W-140 and Dana recommends 75W-140 (see my post above).

Not to start a big discussion, but FCA is chasing MPG and thus the reason they deviated from Dana's recommendations.

These axles run hotter and have less fluid capacity versus prior generations and (for me) I want the extra protection so that is why I recommend 75W-140 versus 75W-90.

 

[Rhinebeck01]

@Rhinebeck01 can you expand on this? Curious what changed your mind. You can PM me if you don't want to start an oil holy war.

"I used to use 75-90 for the front and 75-140 in the rear .... but these days I use 75-140 in both front and rear.

If you do your homework, you will learn 75-140 in both front and rear, is a good / better way to go. "

I still have some 75w-90 on hand that I'd rather not toss out. : )

@BDinTX

DO use that 75-90 you have on hand... no reason not to if you have that on hand / you purchased already.

Next time you order though, do consider buying just the 75-140 and using that in both front and rear. A bit better diff protection. Easier to deal with just one weight of fluid when ordering, doing the diff fluid changes.

I also use PINK Teflon Tape these days. For years I use yellow Teflon tape for the diffs but recently switch to PINK. Research about PINK Teflon Tape.

I use this now a days... Nice to work with.. More stout.. Industrial Grade 1296” Pink Plumbers Teflon Tape, Gas Line Pipe Thread Tape...,

Yes, I used up all my yellow Teflon tape first, then moved to the femi PINK color tape.

I'm an old guy but stay current with things so to speak...

https://www.amazon.com/D-N-Premium-...7e-82ef-ded41293973d&pd_rd_i=B08L9B9BK8&psc=1

 

[CarbonSteel]

@BDinTX

DO use that 75-90 you have on hand... no reason not to if you have that on hand / you purchased already.

Next time you order though, do consider buying just the 75-140 and using that in both front and rear. A bit better diff protection. Easier to deal with just one weight of fluid when ordering, doing the diff fluid changes.

I also use PINK Teflon Tape these days. For years I use yellow Teflon tape for the diffs but recently switch to PINK. Research about PINK Teflon Tape.

I use this now a days... Nice to work with.. More stout.. Industrial Grade 1296” Pink Plumbers Teflon Tape, Gas Line Pipe Thread Tape...,

Yes, I used up all my yellow Teflon tape first, then moved to the femi PINK color tape.

I'm an old guy but stay current with things so to speak...

https://www.amazon.com/D-N-Premium-...7e-82ef-ded41293973d&pd_rd_i=B08L9B9BK8&psc=1

Or if you want to switch "genders" (totally a joke here), you can use blue tape (which is specifically for petroleum):

https://smile.amazon.com/Millrose-70660-Monster-Thread-260-Inch/dp/B00K80KTR6

 

[BDinTX]

lol well I went with ARB diff covers for the +10 HP the red powercoating provides. They have fill/drain ports with o-rings so I get to stay gender neutral.

 

[Rhinebeck01]

Or if you want to switch "genders" (totally a joke here), you can use blue tape (which is specifically for petroleum):

https://smile.amazon.com/Millrose-70660-Monster-Thread-260-Inch/dp/B00K80KTR6

@CarbonSteel

I'll stick with the femi PINK stuff I mentioned. Trans over .... Try that one.... and you will see that the greater density, etc. makes it real nice to deal with/to use and probably does a better job at thread sealing, etc..

 

[CarbonSteel]

@CarbonSteel

I'll stick with the femi PINK stuff I mentioned. Trans over .... Try that one.... and you will see that the greater density, etc. makes it real nice to deal with/to use and probably does a better job at thread sealing, etc..

I have two rolls of the blue and it is very thick. Truth be told, I have never had an issue with any verson of teflon (when the proper type is chosen for the fluid or gas) and have used more of it than I want to remember from my days of working in the petrochemical industry.

White, yellow, green, gray, and red, I have used them all...

On a zero pressure plug like a differential has, it really will not matter what type you use as long as you apply enough of it and tighten appropriately.

 

[Rhinebeck01]

I have two rolls of the blue and it is very thick. Truth be told, I have never had an issue with any verson of teflon (when the proper type is chosen for the fluid or gas) and have used more of it than I want to remember from my days of working in the petrochemical industry.

White, yellow, green, gray, and red, I have used them all...

On a zero pressure plug like a differential has, it really will not matter what type you use as long as you apply enough of it and tighten appropriately.

@CarbonSteel

I hear ya.... I use my Teflon tape on more then just diff plugs though.

All I can tell you is..... a cross the board... whatever I use it on...... I find the PINK easier to use in regard to application....

IF someone gives me a decent roll of yellow for free.. hell yah, I'll go back to using yellow.. IF I buy though right, now I will buy PINK.

 

[Chupacabra]

I put 140w in my rear diff 2,500 miles ago and have noticed no difference at all in MPG.

 

[jbcrane]

Read this whole thread and I feel *mostly* confident, but there's a lot of opinions and little data.

I have a '21 Sahara with LSD + tow package. It's my daily driver, and I get it out for light wheeling maybe once/quarter (which sucks, but that's another topic). Don't really tow (got the package for the aux switches really).

Just hit 20K miles.

Watched a video on how to do it - seems easy enough. Will make sure I have yellow teflon tape and 2qts of fluid, but which fluid?

90 - mostly recommended, listed in the service manual?
140 - better protection cause it's thicker, but not entirely necessary. Might drop my MPG slightly.

Leaning toward the Valvoline flex fill 140 for both front/rear. Royal Purple is ~$5/qt more - worth it for my usage?

Hey Ricky,
I went through this a few months ago and received a ton of good advice from the guys offering recommendations here. It being my first time, seemed a little gripping at first, until I got into it and realized it's pretty easy. The big thing too is - don't over-tighten the bolts around the diff cover if/when you remove and put it back on. There's a lot of chatter about how tight is too tight. I think DANA says 25-30. I stopped just north of 20. The factory gasket should be re-usable at 20k miles. It's nice, with metal inserts around the bolt holes. As others have mentioned too, make sure to get the fill plug out first - before you drain it. Have fun! Oh - and I went 75-90 in the front, 75-140 (RoyalPurple) rear for all the reasons everyone mentioned (the Valvoline pouches eliminate the need for a pump, like the RP bottle would benefit from). Mine too is Anti-Spin M220 rear/Open M186 front. And the DANA nodular iron in grey gets my vote for best looking Diff covers ;-). Have fun!

 

[rcadden]

Hey Ricky,
I went through this a few months ago and received a ton of good advice from the guys offering recommendations here. It being my first time, seemed a little gripping at first, until I got into it and realized it's pretty easy. The big thing too is - don't over-tighten the bolts around the diff cover if/when you remove and put it back on. There's a lot of chatter about how tight is too tight. I think DANA says 25-30. I stopped just north of 20. The factory gasket should be re-usable at 20k miles. It's nice, with metal inserts around the bolt holes. As others have mentioned too, make sure to get the fill plug out first - before you drain it. Have fun! Oh - and I went 75-90 in the front, 75-140 (RoyalPurple) rear for all the reasons everyone mentioned (the Valvoline pouches eliminate the need for a pump, like the RP bottle would benefit from). Mine too is Anti-Spin M220 rear/Open M186 front. And the DANA nodular iron in grey gets my vote for best looking Diff covers ;-). Have fun!

Uh.....my understanding (from watching videos, admittedly I haven't gone out to look at my actual axles) is that I have two plugs - a fill plug and a drain plug. I remove the fill plug first, then do the drain plug, then put them back in reverse order to fill.

I hadn't planned on actually removing the covers. Do I need to?

UPDATE: Just went and crawled underneath - I definitely have both drain and fill plugs on both pumpkins.

 

[jbcrane]

Uh.....my understanding (from watching videos, admittedly I haven't gone out to look at my actual axles) is that I have two plugs - a fill plug and a drain plug. I remove the fill plug first, then do the drain plug, then put them back in reverse order to fill.

I hadn't planned on actually removing the covers. Do I need to?

No, you don't need to remove the covers if you're just changing fluids. The reason to take the fill plug out first is sometimes people drain it first - then aren't able to get the fill plug out. Now your diff has no fluid and you're kinda screwed. It's just a precaution.

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