I just picked up my 3500 three weeks ago. I also picked up a Alpen lite 36rl that is about 13,800 lbs. I put over 500 miles on the truck picking it up this last week. Does the diff oils need to be changed? I have reviewed some of the posts and am a little confused :help2: . Can anyone help?



Tony

I say yes. I changed mine after 1500 miles and it was loaded with metal filings.

In your case I would change it. And then keep an eye on it. If it starts to darken then change it again.
I ran mine 500 unloaded then 500 loaded. Lots of short trips and heat cycles, then changed the oil.