I always read the owners manual, it doesn't say to change it if towing, it says to change it if "frequent trailer towing". So what does frequent mean? weekly? monthly? What if I tow 3 times a year? If I tow infrequently when do I change it?

Inspect the front and rear axle fluid,
change if using your vehicle for police,
taxi, fleet, off-road or frequent trailer
towing.

 

Thats what it says on every 18k service interval. So if I don't use my truck for any of these things the diff never needs changed.lol

 

This is real easy, if you have the lifetime warranty and you don't have jimmy bobs towing, macon police, snowplowing from us, Akbars Taxi on the side change it every 25-30K especially if you have the LSD and save reciepts of product bought, lifetime trucks follow to keep warrany in service, we all know how harsh we run our trucks and this is a simple service to provide lasting use. You don't have to have Dodge do the service to keep the warranty in service just make sure you doc. date, miles on the reciept, if you don't do it well thats your right, my dad had two 4 wheel drive vehicles from chevy, never changed the oil and no problems well over 200,000 miles on both and of course they were not LSD with the clutches, if you have the LSD I would def. do the service. Just did mine cost $42 and 1 1/2 hours of time, time well spent drinking a beer and enjoying the day.

 

perfectly said

 

You can count me in with this crowd. I think the engineers that designed these things know when thay need to serviced. I went through my whole mantance book and it never said to change the fliuld unless frequent towing,dusty conditions,fleet cars such as taxi and police cars ect. I will do only what warrenty requires. Throw your money away if you want to. Oils and grease are far better now than in times past. In the 60's and 70,s You didn't have to change rear grease untill 100,000 miles.

 

Got my front and rear diff fluid changed with synthetic today. The fluid was def brown and needed to be replaced thanks for the advice guys. My odometer is at 23k.

 

Interesting post, I purchased my first truck 13 years ago and put 450,000 on it had the diff changed at 315,000 as Axel bearing were going. Asked a couple of times at the dealer and everyone looked at me like I had 2 heads. Chevy dealer, I still have the truck Z71 5.7 4x4 and it's been 185,000 since it's been changed. Great place to learn about my new ride. All the sins are here so I guess I rather be safe than sorry, but than again if the 3.55 go maybe time for 3.92. Good info guys.

 

I changed mine at 30k exactly. It was black and smelled like crap. I only did it to clean out the break in metals, replaced with RP and probably wont be worrying about it till I get to 120k miles.

 

I was pulling a trailer and didn't even think about the diff fluid. My first oil change on the road and the tech comes out to start the upsell. I hesitated and he said he'd love to show me the fluid in my truck. It was black. Truck might have at 10 or 11K at that point. The kid said he wouldn't have thought a thing of it if he hadn't seen that big ole hitch on there. Glad he checked. It was bad and worth every penny of whatever it cost.

BillO