Just checked on the Mercedes website to see what they recommend in the G56.

They say: Getriebeöl SAE 80, 80W for the g56-6
So that brings you to "235.1 Getriebeöle (Spezifikation 235.1)" and lists these oils link.

Oh well, no ATF, etc.
I think I try that RP syncromesh stuff...

 

whats wrong with atf works fine. thats all i run.

 

I guess I'm not real sure on why you were looking there to find out what oil to use. If you lived over there you probably can't find ATF+4 but over here it has been tested and approved for use in the G56.
The ATF+4 is all I run in mine and have zero issues.

 

I just found it interesting that the manufacturer of the transmission asks for a different oil... not ATF. I read the comments about "saving money" at the plant, where they do the initial fill, by using ATF for everything....makes sense to me.

I wonder what really belongs in the transfer case too...

 

tell ya what run something else in it and see how that warranty works out.

 

I agree, if the warranty would be still active, I would go by the "handbook".
Truck has 60k now and I think that's it in terms of warranty...?

Actually, now that I think about it, the truck might have a 100k/5y warranty, right? 2007 model...

 

not on the drive train. I have ran 2 g56's towing avg gross of 35k and have not had any issues other then on my 07 they put bad oil from the factory.

 

Standard Transmission's recommending Pennsoil Synchromesh after seeing lubrication starved damage in G-56's using ATF+4. One quart over is suggested also.

I switched to it but can feel no difference in shifting,aside from cold weather performance which was actually a dab better with Amsoil's ATF.

My local shop here just took in a 2006 w/G-56 with shot synchros in 4th gear. They're going to switch out the fluid for Pennsoil and see if it helps.

 

Was planning on changing mine in a few days was going to use royal purple atf but would like to know if any one has used the syrnomesh,and did it work any beter.

Just wanting to know

 

I also change my tranny fluid every 40 t0 50k like it should be. You can run what you want but if that fluids wrong it sure not gonna be cheap.

 

I have 50K miles on mine, no oil change yet and no issues. Folks remember - these trannies are not race trannies. They shift slow. That's why a guy who could have profitted from installing a short throw shifter in mine actually talked me out of it for this reason. I would use what Mopar recommends - ATF+4. The overfill is a good idea though even a Dodge mechanic recommended it to me.