2020 4x4 transmission 8HP75 w/3.92 axel gearing

[corvettejohn]

The shifting pattern is 500 RPM later than my previous 2015 w/ 3.21 gears. I talked to RAM and the dealer about this with no satisfaction. I don’t want to jeopardize the warranty on my truck, 5.7 hemi in both trucks. Any ideas, thanks

 

[CG2742]

Different gearing will produce different results in the rpms. Not sure what your question or issue is. Only thing for transmission is to flash it.

 

[crash68]

Looking at 6th gear(1:1) in both trucks:
2000 rpm, 3.21 gearing, 33" tires: 61 mph
2500 rpm, 3.92 gearing, 32" tires: 61 mph
(both mph were rounded to a whole # and the rpm gap would be closer if your '15 has 31.5" tires)