Part of my 5.9 build is replacing my trans with the 46rh, will be setting this up for general truck use and towing and heard that the Diesel Straight Cut Gears will fit in the trans, and take the friction off the thrust washers so basically you can tow with OD on. Question is what gears work? is it the ones from the 57RE trans or what can they come out of?

 

I know there are a few posts that state that as well. But you don't really need to strengthen up the gears for just a 5.9. They 46rh is made to handle the 5.9. As for not towing with OD it is due to the clutches of the OD, they will start to slip if over done. So a gear swap will not help with that situation.

 

"leave the OD off unless you install the diesel straight cut gears
straight cut gears take the thrust off the thrust washers which otherwise fail with expensive results"

My thought was that almost all the gearing was swapped with the clutch assemblies for that to work like that, curious if this guys post about thrust washers holds any truth. Towing in OD would be nice for mileage since I would't be turning 3-3.5k rpm only going 60mph