So many questions

[Tdawg]

Well all I'm wondering what I should or should not be changing on my truck it now has 1300 miles on it I've heard some ppl are changing the spin on allison filter at 500 miles, is this something I should be doing,,if so how much fluid do I use and what kind,,,

Also wondering about Diff fluid ppl are telling me to change front and back,,again what kind of fluid and how much,,thanks for all the help guys,,just trying to make this truck last...


Anything else I should be changing let me know ...Thanks

[Idle_Chatter]

There's been a lot of discussion on these questions, Tdawg. It all boils down to your personal choices regarding your concern for reduction of "break-in" damage to your vehicle and sense of freedom for going away from factory "recommended" (note: I did not say "required") lubricants. I intentionally and purposefully did some early changes to remove break-in contaminants and assembly scrap. The allison spin-on is a good idea at 1000 to 1500 miles. I did mine at 1500. Get a replacement from an authorized Allison Dealer ($8.25) or from Greg Landyt www.lubespecialist.com do not pay the Stealer $32 for this filter. You will only lose about 8 oz of fluid taking the filter off. Prefill the new filter with Dexron III equivalent ATF and you shouldn't even have to adjust your tranny level when done. VERY IMPORTANT! when you (or whoever you have do it) remove the old filter - there is a ring magnet stuck to the top of the filter. Remove, clean and reinstall that magnet on the new filter before replacing! I had my filter changed at a Jiffy Lube place without being aware of the magnet and into the dumpster with the old filter went my magnet. Stealer wanted $19 for a new one. I bought it at an Allison Dealer for $1.86!
The 500 miles is for the differentials. The hypoid gears in the differentials are "fit" in the factory but actually lap into each other in use. This produces a lot of wear metal and heat. The heat can break down the lube and the wear metal is abrasive grit in your lube. I was in Wisconsin and getting ready to take a long trip right at break-in. I drove my first 500 miles and even about 150 miles on dirt roads in 4wd to get some wear-in on the front diff. I had the dealer do engine oil & filter and both differentials at 500 miles. The rear requires synthetic lube. The factory lube is called "grape juice" (because of it's smell) and costs about $30 a quart. The front is petro 75w90 gear lube. I would recommend going to 75W90 synthetic lube in both diffs at 500 miles and again at 30,000 and every 30,000 thereafter. Sometime between 15,000 and 30,000 it wouldn't hurt to drain the transfer case and add fresh Dexron III ATF. Engine oil: I changed oil and filter at 500 (along with the diffs), to get the assembly and breakin stuff out. Then again at 1500 (along with the allison spin-on), then at 3000. I made a couple of more changes in between 3000 and 7500, but at 7500 I started a 7500 mile routine that I'm still holding to and my oil analyses have been great so far. Fuel filters: 15,000 is recommended and should be a maximum. Some people are changing at 10,000 and some are going farther. I changed at 15,000 twice and when I cut my second filter open and looked at the contamination of the filter I was a believer on the 15,000. Hope this helps, no warranty is given or implied, individual results may vary, some settling of contents may have occurred in handling. tongue.gif

[MudNurI]

We did our first change at 1K...(dealer recommend) We changed the rear diff, and also switched to Mobil 1 Delvac. We run synthetic oil because that's what the dealer recommended, we were worried about "recommended changes, fluids" as some dealers would/could balk at a warranty issue if it wasn't done to the specs. Some people don't run it, others do. Some people don't change the rear diff either at this interval.

Since your truck is still a baby, I'd stop in the dealers and ask them whats the 1K recommendation..let them do the first one. Our dealer(s) have always done our LOF's and any other recommended interval service. It saved us a big headache when it came time for the NSBU fix...basically was able to say "but only ASE GM Tech's have ever worked on it, " etc.. still took some b*tching, but they covered it. and we were over the 40K mark - closer to 50K....

like idle_chatter said, there are so many different ways people are doing this, it's all a matter of preference. FYI the 1k change for us was just under $300.00

Brandy

[IndigoDually]

The only thing I have to add is I changed the rear diff after about 500 mi of towing of hauling. It takes some weight to get the G80 clutches to break in. When they break in they will discolor the fluid with friction material.

[Tdawg]

I appreciate all the great responses,,I've allready changed my engine oil at 1000, with Rotella and will change again at 3,000 and 5,000 then switch to Amsoil Synthetic,,I havent towed with my truck yet I'll have to go borrow a friends bumper pull and pull it around for a cpl days because I dont have a goosneck ball in the bed yet,,I'll then change the Diff fluid and the spin on allison filter,,,thanks again for all the help