So im gonna hit 15000 miles soon so said but when should i change the fluids.

 

I am not sure what the change interval is, but I have always believed the first one should be done very early. A couple of thousand miles would be my opinion. I just changed the fluid in both axles at 1800, and I'm glad I did. There was a little bit of gray stuff suspended in the oil and some stuck to the magnetic plug. Not a big deal. But enough to make me want to drain the "break-in" oil and start fresh with clean oil.
The owner's manual says to change the manual transmission fluid @ 30,000 miles. I have always done that on all my manual tranny vehicles, and did the axles at the same time.
Some people NEVER change axle oil and get long term service out of their axles. I like to be on the safe and peace-of-mind side.

 

thanks so i prob get it done when i get the lift installed

 

I think 15K is the recommended interval. It's so easy to do I would recommend doing it.

 

The dealer gave me free maintenance for 3 years on my Jeep when I purchased it. I figured why not, it doesn't cost me anything and if gives me a reason to look at new models and talk shop with the techs.

I'm due for my diff fluid to be changed, 15k miles, I found out that this isn't included in the maintenance plan..

I decided it shouldn't be a big deal I'll do it myself. When I told the dealer this they told me that they use a "Special Manufacturer specified additive" for the LSD and the cost of the additive is $110. The cost of the entire service is $170, so I "may as well have them do it".

Is this a classic case of a stealership trying to get away with something?

Is there any reason I can't throw some syntehtic in there and call it a day?
Which synthetic do you guys prefer?

 

I'm using Mobil 1 synthetic. No special additive, even though I have the Lim Slip Diff. Did it myself for, I don't know, $40-45 in fluid?

For more info on this, be sure to read Wayoflife's article:

Differential Fluid Change Write-up