[yellowismellow]

went to the dealer today for a 12,000mile service. tried getting 400 bucks outta me to change the diff fluid, air filter, and lube the chassis. hell, i can go to napa and get everything i need for under 60. so i told the guy to just do my free oil change and that i've worked on jeeps for 6 years now and know how to do pretty much any repairs and services to my jeeps.

real quick tho, this is my first jeep i bought new with only 65 miles on it new.

when SHOULD i change the diff fluid? ive put it in 4wd twice for under 20 miles each time.

also, what brand fluid should i change to when its time?

[VinoTJ]

I went with Amsoil full synthetic after I got my gears & lockers done (after break-in with dino of course), just after 12k miles. I have dunked my heep in water/mud a few times, plus I changed my diff covers to HD ones - so I have changed it a couple of times already.

I do not plan on changing it for some time with the Amsoil in there.

I got my fluids from Chuck at www.sor4x4.com including diffs, tranny & tcase. The 6-speed shifts SOOOOO much smoother with the amsoil in there - especially in the cold!

[90SaharaJeep]

schedule B I believe states that you should change it every 12k miles. Really very easy to do. HERE is a nice easy to follow write-up:

$400??? hahaa!

[Dogman]

I change mine about once per year. It's really dry here, so not much mud/water.

I would do that all day for $400 a pop

I use this: http://www.valvoline.com/pages/products/product_detail.asp?product=2

[rouxbicon]

Your owners manual will tell you to change it every 12,000 miles IF you offroad frequently or tow frequently. Otherwise it mentions no diff service interval. Like many other modern vehicles the differentials are considered "lubed for life" for normal use.

I don't tow frequently or offroad frequently (unfortunately), but I personally am still a little reluctant to never change the diff lube. I compromised and settled on a change interval of 30,000 miles. I believe this will keep my diffs in good shape, and I will of course increase the frequency if/when I get the chance to hit some trails more often.

[yellowismellow]

hmm...i kinda just want to change to synthetic just to spite the service department at my dealership.

[BYuen]

If you've got the time go for it! Nothing like working on the Jeep and changing the fluids etc. Synthetic as always great. I prolly end up changing my diff fluid twice a year, depending how many times I have to go rescue my friend who likes to swamp his Jeep . I think it's such a rip off that the dealership charges 100 bucks per diff fluid change when you can do it yourself for less than 20 bucks in about 30 minutes.

[carpekd]

I'm glad ya'll posted this...It reminded me that I need to change mine

[RixJeep]

Wow, $400 for a 1/2 hour worth of labor and some parts and lubes? Yep, that is a total rip-off. Here are my suggestions. Go synthetic for everything. I happen to use Amsoil, but there are others. Amsoil has the most comprehensive coverage for Jeeps (and anything else). I use the Severe Gear lubes in my diffs, t-case and trans (5 sp). The engine gets Series 2000 0-30, the PS gets Universal ATF (which is also good for the automatic trans) and I use the Racing grease for all lubeable joints. Amsoil's website has info on how often you need to change lubricants. I do modify those recommendations according to my use, Mostly though I get under my Jeep and do a lube job after almost every run, mostly because I am either in water or severe dust. I also do oil analysis after the first year of use and every 2 years thereafter. The thing about synthetics is that they are much more resistant to degradation by heat , they have longer change intervals and they offer much better wear resistance. They cost more initially, but less in the long run. My background? I was a fire apparatus maintenance officer for 24 years. I hope this helps!