2006, 5.9 Cumminis, NV5600, standard cab. Any overdrive suppliers beside GV? The truck has a split drive shaft already, so a divorced unit is a possiblity. Shopping price and hard to believe GV is the only game in town.

 

Is your truck a 4x4 if so the US gear calls for shortening the rear driveshaft and lengthening the front one. It goes between the transmission and the transfer case. I have driven both the US gear and the Gear vendors and the Gear vendors is what I bought I have over I00.000 miles on it with out any problems.
Jim O

 

06 is g56 tranny and none of them recomend towing heavy

 

I was in the same dilemna as you. US Gear doesn't offer anything for the G56 trans. The Gear Vendors unit cannot be used with the exhaust brake engaged.

There is a company called Mitchell Manufacturing that makes very heavy duty OD Gear splitters...although, I think they stopped production of some models.

I found one used, model 3500D, that is an 18.2% overdrive. It is rated conservatively at 35,000 lb GVWR, and is synchronized gear-to-gear drive.

I'll post pictures when I finish up the details of installation. It mounts in a divorced configuration, and the rear drive shaft has to be shortened.

With the OD engaged in 6th, I'm at 1650 rpm at 75 mph, and 2300 rpm at 100.

--Eric