First oil change

[Wege]

I just received my 04 2500hd, traded in a 98 k3500 6.5. What a difference. Anyway was wondering about oil, rear and front differentials. I wont be doing any serious towing till spring. I usually haul (400)20 at a time, 1000lb round bales at a time, 10 miles from the field to my house.
Also read that not many people recomend the K&N air filter. Is the UNI that much better?

Any opinions would be greatly appreciated.

[DinoMax]

wege, congrats on the new truck, and welcome to the forum smile.gif GM recommends the diff fluid be changed after the first 500 miles. Seems there is an issue with very small metal particles/shavings occuring while the new gear wears in. As for oil changes, everybody seems to have their own opinion. I would suggest an oil/filter change after the 1000 or 1500 miles, just to get rid of anything that may be present from initial break-in or the casting process. After that, just get on a regular schedule and stick to it. Some go by mileage, others by hours (if they have a lot of "idle" time on the motor). I think most would agree, under fairly normal circumstances, every 5000 miles is sufficient. That is what I do, and no problems to date (27K on my truck). Also, many have received notice from GM that fuel filters should be changed every 15000 miles. If you don't, and have fuel system issues, they may not warranty it. Just keep receipts and/or a log on all services performed, and you should have lots of trouble/worry free miles with your new rig. Good Luck, DinoMax :D :D

[JimWilson]

I'm running 100% Mobil 1 in everything, including my engine (and even the grease I use on the frontend!).

I did the rear diff at 1K. I did the front diff and tcase at 5K. Had the tranny flushed around that time too.

[HD-Nate]

Wege, congratulations on the new D/A you will love it.

Going to a synthetic like Delvac1 seems to be very popular and I have done so also. Since I run Mobil1 in the rest of my cars/trucks it was a natural choice.

Some say that you should not go to a synthetic until at least 10k miles. I changed my Dino oil out at 5k and went to synthetic at 10k.

The dealer gave me my first lube and oil change free at 5k. I asked them about the differentials, they stated