Just bought my first H1, it is a 2004 open top in metallic black with 5" RD lift and 39.5 IROKs. Fun truck, slow as hell but fun truck.

Came with tons of factory service manuals and the such, I'll follow the maintenance schedule religiously as I do all my vehicles but is there anything out there from you owners who know from experience what I should look out for or keep my eye on more than normal?

For oil I was planning on using Rottela T6 and an Amsoil filter, any issues with that? Was going with Amsoil or Royal Purple for the gear oil and hubs, trans, and transfer case. However the owners manual threw me for a loop. Axle assembly(diff) if checking fluids and they are low it says to add 80W90 gear oil, yet if servicing to use 'Hummer H1 Synthetic gear lube (75W90) with friction modifier.

SO when I flush and refill with fresh fluid I use 75W90 with a single 4oz tube of fiction modifier? both ends?

 

The Eaton electric lockers require the specific OEM friction modifier. I use the 80/90. The rest sounds fine. I am in Waco.

 

good to see a new owner. Let me know when you are in Austin...