I bought a 2002 Jeep Grand Cherokee laredo with selectrac from a private owner with 60K on it. I am in the process of changing all of the fluids since the guy a bought it from didn't keep many of the service records. I have records of the pinions seals and u joints being replaced at 50K, but I am not sure if those processes required a complete fluid change. In changing the fr and rear differential oils, would it be sufficient to use a suction gun to extract the old fluids or do I need to take the covers off to do a proper job? The seals both are dry and holding well.
Jeep differential fluid?
don't use a suction gun. remove the cover, get a couple cans of brake cleaner to remove all the metal. metal constantly comes off the gears and the bearings due to normal wear. it builds up on the magnet and all interior surfaces. when you put it back together you will need a little more than 4 quarts of 75w140 synthetic. that is the only lube you should use on it. you also need to add a bottle of mopar limited slip friction modifier to each axle for the varilok system. change the fluid every 12,000 miles.
Jeep differential fluid?
I have used the suction gone and I have pulled the cover. I have a wrangler with ARBs and after 40k miles my oil still looks almost new and no metal. I have a grand with over 150k miles on it. The diff fluid was changed about 70k and that was it. I should probably check but it doesn't see the abuse that the wrangler does.
I have always used an 85 or 90 weight, I haven't used synthetic.
