New G56 overdrive ratio?

[Mathew Clausen]

I hear from a guy I know who works for MB transmissions that there is a "new" version of the G56 trans for the 6. 7L (and maybe the last of the 5. 9's?) that has a 0. 742 overdrive ratio (ILO 0. 79). Has anyone noticed this? Seems like it would be a very nice improvement in general - 0. 79 sounds pretty busy at freeway speeds.



He also indicate the new parts could be swapped into existing transmissions.



Mathew

 

[AKaiser]

I hear from a guy I know who works for MB transmissions that there is a "new" version of the G56 trans for the 6. 7L (and maybe the last of the 5. 9's?) that has a 0. 742 overdrive ratio (ILO 0. 79). Has anyone noticed this? Seems like it would be a very nice improvement in general - 0. 79 sounds pretty busy at freeway speeds.



He also indicate the new parts could be swapped into existing transmissions.



Mathew

Let's hope. :-laf That would move 65 MPH down to 1900 RPMs on stock 265s (31-32") and make it 1825 RPMs on 33s. Right now, stock tires put 65 MPH at 2033 RPMs. That's a 200 RPM drop by going from stocks with . 79 OD to 33s with . 742 OD. Has to be worth at least a gallon, and would put me close to 20 MPGs. Oo. Add my planned PDR camshaft, etc, and I think I can get 22 MPGs. I plan to keep this thing forever and a day.