Newbie Question

[kodiakoutdoors]

I am now at 500 miles on my new truck (2004). I remeber reading somewhere here that I should do an oil change. I can't seem to find it with the search engine. My question is, when and what fluids should I change (if I need to) and when should I change to synthetic? I could just follow GM's recommendations, but I think many of you here have your own opinions and I would like to here them. Thanks!

[letsgo]

The 500 mile reference is in reguard to the rear differential. It is suggested buy GM that after towing for a distance of 500 miles you change the differential oil with the original synthetic oil 75W 90 or heavey duty towing 75W 140.
It has been suggested by the members that all your oil levels be checked, you may be suprised and find that some levels are lowwww.

good luck

[kodiakoutdoors]

thanks for the info. i will check the fluids and change the rear diff. although i do not tow anything. thanks again.

[Idle_Chatter]

Welcome, Kodiak. The 500 mile recommendation on the rear diff originated with Eaton (who makes the rear locker) and wasn't only for towing. There's a "lapping in" process on the rear gears that can produce heat and debris in the breakin process. It's also not a bad idea to get an early change on all your lubricants to get any break-in and leftover assembly products out of the system. I did both my diffs after 500 miles (including some break-in miles run in 4wd on my front diff) and also my engine oil at 500, 1500 and 3000. I also swapped out the Allison spin on filter at 1500 (DON'T FORGET the MAGNET!) The DMax engine is known to produce some wear metals during break-in, especially copper. I've got nearly 74,000 miles on my 2001 now and took extra lubrication changes early because I plan to keep this truck for the long-haul.