MAINTENANCE : Jeep JK Wrangler Differential Fluid Change Write-Up

I went through all the post but I'm still a little unsure if synthetic gear oil is alternative of adding the friction modifier? Basically if you go synthetic, you will not need the friction modifier?

Correct all synthetics will have the friction modifier already in it
 
Hey guys. So appreciative of all the great info. I just bought a JK Sahara with 70K on it. I did both axles (Lucas Gear Oil 80W-90) & the transfer case (Carquest ATF+4). I filled everything until it started coming back out & sealed em up. I read on another site that too much oil can cause foaming? Also, what if there was some ATF in the hand pump when I put the gear oil in & vice versa? Not a lot, I pumped it out as best I could and even pumped some new fluid in to force the old out. I felt like it took a little more gas to get it rolling to 40 or 50 mph today & it was my first DIY so I'm being paranoid. No weird smells or anything.
 
Hey guys. So appreciative of all the great info. I just bought a JK Sahara with 70K on it. I did both axles (Lucas Gear Oil 80W-90) & the transfer case (Carquest ATF+4). I filled everything until it started coming back out & sealed em up. I read on another site that too much oil can cause foaming? Also, what if there was some ATF in the hand pump when I put the gear oil in & vice versa? Not a lot, I pumped it out as best I could and even pumped some new fluid in to force the old out. I felt like it took a little more gas to get it rolling to 40 or 50 mph today & it was my first DIY so I'm being paranoid. No weird smells or anything.

As I asked in your other post, are you running factory diff covers or aftermarket ones with fill holes that are higher? If the later, you did fill it up too much and your ring gear will pump out fluid through the breather tube. If you have factory covers, you are fine.

Regarding the ATF, how much is "some"? If you literally just had a bit in the pump, you should be fine.
 
I've brought my jeep through some deep water down here in the swamps of florida needless to say it was apparent when changing my diff fluid in my 2015 jku rubicon. I'm going to extend the breather hoses on my D44s but I was wondering if I need to change the fluid in my auto trans or transfer case? The deepest water I've forded is about to the top of the front fenders (I have 2.5 inch lift and 35s) if so what fluid should I use and how much? Thanks!
 
Well, I gotta say....I was quoted for $500+ to change the fluids at a dealership service.....I was NOT happy with the possible bill.

So, then I did some research...a lot of people are saying they heard the same price tag too and some mentioned they did it themselves. I decided to do it after finding this write up. It was so easy!! Thank you for this write up!

Total savings....around $450 -- I see myself ordering more mods soon! :)
 

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Just changed mine after reading this last week. Didn't realize how simple it was to do. Only issue I ran into was adding the fluid back into the front axle. Had to use a short piece of tubing from the axle access hole to my bottle of axle fluid. The front track bar was in the way.
 
I have a 2013 JKUR and spyder diff covers, there made to overfill. How much gear oil would I need?
 
I have a 2013 JKUR and spyder diff covers, there made to overfill. How much gear oil would I need?

Unless you want a big stinking mess on your hands, you DO NOT want to overfill your diff. You WANT to run what is recommended from the factory OR as much fluid as is needed to reach the bottom of your axle tubes. Anything more is too much and it WILL pump out of the breather tubes.
 
Unless you want a big stinking mess on your hands, you DO NOT want to overfill your diff. You WANT to run what is recommended from the factory OR as much fluid as is needed to reach the bottom of your axle tubes. Anything more is too much and it WILL pump out of the breather tubes.

Ty that's what I have always done. since i first read your write up awhile ago!
 
I'd like to attempt this service but my problem is I don't really have a flat surface to work on. The street is about as flat as I can get but it has a pretty good crown to it. Do you think this would be a big problem since the axle would be higher on one side? I really don't want to pay the dealer to do this.
 
I'd like to attempt this service but my problem is I don't really have a flat surface to work on. The street is about as flat as I can get but it has a pretty good crown to it. Do you think this would be a big problem since the axle would be higher on one side? I really don't want to pay the dealer to do this.

I'm getting ready to do mine in my slanted driveway. This is the first time I'll be doing this on this much of a slant. I plan on draining the fluid with the vehicle in the driveway, putting the cover back on and adding one quart. Then back it into the flat part of the street by the curb and top it off to the correct level. I have pushed tons of vehicles in and out of shops with no fluid in the diff, as long as speed is low, there is enough residual fluid in the bearings to not do damage while moving the vehicle that short of a distance. The other thing your could do is purchase some of those mobile drive-on ramps to level things out.
 
I'm getting ready to do mine in my slanted driveway. This is the first time I'll be doing this on this much of a slant. I plan on draining the fluid with the vehicle in the driveway, putting the cover back on and adding one quart. Then back it into the flat part of the street by the curb and top it off to the correct level. I have pushed tons of vehicles in and out of shops with no fluid in the diff, as long as speed is low, there is enough residual fluid in the bearings to not do damage while moving the vehicle that short of a distance. The other thing your could do is purchase some of those mobile drive-on ramps to level things out.

That's a good idea with the ramps to level things out a bit. I think I'll give that a try.
 
I was at the dealer today getting one of those "free" oil changes and thought I'd inquire on a front and rear diff services. They wanted close to $350 for this! Needless to say I'll be doing this service myself really soon!
 
I was at the dealer today getting one of those "free" oil changes and thought I'd inquire on a front and rear diff services. They wanted close to $350 for this! Needless to say I'll be doing this service myself really soon!

Yep. It's usually an hour labor for each diff. You figure at ~120/hour that's 240 right there. Then there's fluid and rtv/gaskets, shop supplies, and tax. Gets more expensive if friction modifier is needed for LS clutches. It pays off to do it yourself.
 
Thanks for the great write up. Went to get some diff oil at O'Reilly's. There was not a lot to choose from and I ended up going with this. Apparently a house brand produced by Valvoline. Anyway it was on sale for $13.99 for a gallon. Anyone with any experience/ comments on this stuff good or bad before I go throwing it in this week? Thanks.ImageUploadedByWAYALIFE1455668103.570786.jpg
 
Thanks for the great write up. Went to get some diff oil at O'Reilly's. There was not a lot to choose from and I ended up going with this. Apparently a house brand produced by Valvoline. Anyway it was on sale for $13.99 for a gallon. Anyone with any experience/ comments on this stuff good or bad before I go throwing it in this week? Thanks.View attachment 188361

I use that stuff most of the time but I also change the diff fluid a lot.
 
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