Just did a quick search and cannot find out the frequency for oil changes of the G56. the manual only deals with the Auto tranny.

 

Actually on my 2007 5.9 G-56 truck I looked in the owners manual and it says 60,000 miles for severe duty. DOes not list a fluid change for non severe. I tow pretty heavy in hot temps so I switch mine out every 20,000 or so with amsoil. With the price of fuel I might go with the MOPAR brand from Wal Mart. ATF+4

 

I was looking at changing mine with amsoil but if your going to go back to mopar must not be worth the price difference huh?

 

I want to SEE if it makes any difference. On my 06, my trans went from Clunky to smooth. My 07 has the NEW G-56. It shifts the same either way so I might give the MOPAR stuff a try and see if there is a difference. If so, then AMSOIL is only one click away! LOL

 

Hey Guys, not playing Devils's Advocate here, but when I switched slushbox fluid for Royal Purple Synchromax my G56 grew wings....
But I'm out of warranty, so it doesn't matter....anyone who wants info, just pm me....

 

I think my '05 manual states 30K for severe duty and for regular duty it either doesn't specify or says something like 100K or more. Anyway, I change mine every 30K. I have been using Redline C+ ATF, but might go back to Mopar ATF from WalMart too. The Redline stuff works great and made an improvement in shifting and mileage, but money is tight with high fuel prices, so I might save some money and go for the Mopar stuff next time.

 

How many quarts does it take,does it take regular ATF.

 

6 quarts of ATF+4