Mine always seems to shift smooth.

 

I dont like the way my G56 shifts either. Its always felt a bit on the tight side. Ive never had a problem downshifting though.

 

I have found Royal Purple Synchromax to be the best fluid from my experience, in my own truck. I'm out of warranty on the trany, so fluid choice is no big deal.
Even then, my first couple of shifts into third on cool mornings require a bit of finesse with my shifting and then its fine, shifting like a sports car...

 

Are you running the Mopar ATF+4 fluid or something else?????

 

the one that went bad was using factory fluid . i just use atf 4 from my carquest parts house

 

so you have a manual and run the synchro max????

 

Yes. That is correct.

 

my 04 is a pain in the neck to get into 2nd when its hot (Las Vegas at 104) and just as bad to get into fourth when its cold -0 i use ams oil and change it every 30k

 

I love the way mine shifts, I'd rank it as the best shifting truck transmission I've ever owned.

 

Just an FYI, but the reason ATF is used in some manual trannies is due to the tighter tolerances and a heavier oil does not get into all the galleries properly especially under load. To each his own, of course, but that is why ATF+4 is the specified fluid.

 

How long have you run the Synchro and is it thin viscosity like the Mopar ATF-4????

I was told there wasnt enough clearance to run the thicker Tranny fluid because if the aluminum housing????

What about the transfer case?????

 

On my second run of it. It is quite thin, almost like ATF, plus if you look at the Viscosity at 100C it is pretty close as far as the Cst numbers go, slightly thincker.
As far as the almuinum housing issue being a reason for not running a "heavier" fluid, that doesn't make much sense.
I run it in the T case as well...good for a manual trany, good for my tcase.
If you're out of warranty, call the the guys at RP and pick their brains. I did, and tried it hesitantly, but then was quite impressed. Especially when I dropped the first change of it, and there was very little metal on the magnet. Atf+4 had a heck of a lot more metal on the plug!

 

For the 5.9 G56's ... well I guess other than the gearing the new G56 are effectivly identical ... What is the recomended interval?

And just to be sure they specify ATF+4? havn't looked at service manual, just being lazy.

 

I want to say the interval is 60k.

ATF+4 is the fluid

 

I think that's what the book says (60k). I did mine earlier.