I have a 3500 '02 Cummins with 4wd, dually. It has the Dana M80 rear end and posi traction. It also has the 3.55s. I have 385/75/16s on it and when it shifts into 4th at 45 mph the RPM's drop really low and it bogs down. Loaded you either are revving way to high in 3d or destroying the transmission in 4th.


So, for anyone that tows with 4.10s and larger tires, how do you like them? I mainly use this in short trips to work and around the farm. When I go longer distances, I'm often hauling my 10k 5th wheel camper. I am not happy with the performance in the hills with the camper and am hoping this will do the trick. I was thinking 3.73s wouldn't be enough of a change and I don't see 3.92s offered anywhere for this rear end. It looks like 4.10s were a stock option, so any opinions are welcome.


If you have changed yours, what brand do you recommend? Any problems with the Yukon ones that let you keep your carrier or should I get the 4.10 carrier and mopar gears?

 

I changed out to 4:10's on my 2500 1998.5. BUT I run 35 in tires and it was a slight help the rpm is more in the torque range of 2000 rpm. it will help you more with the smaller tires. I have just got back to the stock condition.

 

I have pretty much the same truck except it's got 4.10s and stock size tires. They're just about right for pulling or carrying weight and are fine around town.
I've got a Gear Vendors overdrive that effectively makes them into 3.20s which is really nice when driving on the freeway empty, but all other times I don't use it. The 4.10s put me at 2000 RPM at 60, which keeps exhaust temps down and power up.

 

Thats good to know. Thank you, I think I'll go with 4.10s then. Any brands ro stay away from? I was looking at yukons.