Changing differential gears

valhalla360 wrote:

ScottG wrote:
It looks like our next RAM 3500 SRW will have to have 3.42 diff (unless they change for 2020 with gen 5) so it is entirely possible I will have them changed out for 3.73 or even 4.10 within a couple of years.

You are thinking of the old days with 3 speed automatics when you couldn't get a gear ratio that did what you wanted and the only way to make up for it was a deeper rear end at the sacrafice of MPG when running empty. With modern 6-10speed automatics, they are much better able to keep engine operating in it's ideal HP/Torque range.

It's important to look at the overall gear ratio (between the crank shaft of the engine and the rubber on the road).

To the OP: Take the new ratio and divide by the old ratio. That will give you a rough estimate of what percentage of pulling power increase you can expect. Speed up steep grades will still be limited by HP but if you are not making it up hills or struggling, it will do better relative to the change in ratio.

I understand what your saying and I believe Ram's specs but if you talk to people who have gone from 3.42 SRW's and moved up to a dually with 4.10's, the driving experience is vastly improved even when not loaded. When loaded they're able to get off the line much better which is always a sore point with diesels. I'm hoping the fifth gens have an 8 speed trans to make the 3.42's more palatable (doubtful).