4.88 Gear Ratio Too Much with 37" tires?

[AEV_CUMMINS]

where did you order your stuff from

Truck gear centre. You can find a distributor off of that website showing AAM’s parts

 

[99Cummins]

Truck gear centre. You can find a distributor off of that website showing AAM’s parts

Please provide part #s

 

[AEV_CUMMINS]

 

[AEV_CUMMINS]

I have the factory 4.10s in my 6.4L and will be waiting for 4.88 or 5.13 since I am running 37s. My travels rarely place me on the highway or above 60 MPH so either of those ratios will work great for me. The 4.10s are just a bit too short.

You don't think that the 4.44's would be enough to push you into the right zone? It is pretty much the same jump that I am doing from 3.73 to 4.10 and the fact that Ram offers that jump from factory on some trucks means to me that the .3x difference it makes will make a noticeable improvement.

 

[AEV_CUMMINS]

The percent change from 3.73 to 4.10 is 9.9%
The percent change from 4.10 to 4.44 is 8.3%
The percent change from 33" to 37" is 12.1%

We could crunch more numbers and begin to tell the real story which involves the mass of the new tires and rims compared to the old and how the rotational inertia is impacted even more. This is most obvious when accelerating and along justifies over-correcting with new gearing. Simply correcting the overall drivetrain ratio and matching RPM and MPH with previous readings is fine for cruising .

Ideally you balance between the two and end up with good accelleration and maybe a few more RPMs at given speeds.

Or you can optimize your vehicle for your intended use. I will almost never be on the highway traveling above 60 MPH or so. Most all of my time will be spent on backroads, forest service roads, trails, etc. The additional gearing will be most beneficial for my applications at slower speeds.

Very true and I am happy to hear you are fine tuning your truck to best suit the situations you are going to be encountering with it hopefully as much as possible. Have fun on those back roads!