I can't find the actual mileage recommendation for rear diff oil change. The manual simply says to "inspect" every 18K miles. Unless you see it leaking, that makes no sense. I rarely change the fluid and never before 100K. I have the 3.5 diff that is not LSD. No, I don't use the truck for "police, taxi, fleet, off-road or frequent trailer towing".

I have an 09 1500 with 50K miles that will require its 5 year "inspection" soon. I am planning on changing the plugs, air filter, and coolant. Anything else that I should consider?

 

My 2010 owner's manual doesn't reference changing the axle fluid at all unless you use the vehicle for severe service. You'll find all sorts of suggestions on when to change fluid because of this. Use your own best judgement.

As a mostly meaningless side comment, I just changed the rear diff fluid in my old IS300 after a little too long (90K recommended, it went 126K) and the Mobil 1 I drained out looked as fresh as the day it went in.

Rob

 

i always consider trans fluid change at 50,000-60,000

 

I think that I will change the plugs, air filter, and simple radiator sump drain and refill and call it done. That should supply enough new anti-corosion compounds for 2 or 3 more years.