According to Ashcroft's website on their ratio calculator page: https://www.ashcroft-transmissions.co.uk/calc/ratio_calc.html
Ideal RPMS at 70 MPH would be 2,700. Do you all agree? My own experience tells me that my RPMs are too low, hence the sluggish feeling and constant hunting for gears while cruising on highway inclines, and sudden and harsh downshifts on inclines when I'm trying to maintain an acceptable speed on inclines (like 60 MPH).
I used Ashcroft's calculator with my variables input: ZF 4-speed auto trans, LT230 transfer case, the D2 variant, 3.54 diff ratio, with 33" tires (285/75/16)
The calculator puts my RPMs at 70 MPH at 2,226
at 80 MPH at 2,544
at 90 MPH at 2,862
Below I've uploaded photos of my actual RPMs at those speeds (speed checked with GPS because my speedo is about 10% off).
Lo and behold my actual RPMs at 70.5 MPH are about 2,250 and at 80 MPH about 2,600 and at 90 MPH just below 3,000.
Seems pretty accurate to me.
Now just have to decide if the change should be made to the transfer case or to the differentials. Again, I'm perfectly fine with my low range driveability.
Ideal RPMS at 70 MPH would be 2,700. Do you all agree? My own experience tells me that my RPMs are too low, hence the sluggish feeling and constant hunting for gears while cruising on highway inclines, and sudden and harsh downshifts on inclines when I'm trying to maintain an acceptable speed on inclines (like 60 MPH).
I used Ashcroft's calculator with my variables input: ZF 4-speed auto trans, LT230 transfer case, the D2 variant, 3.54 diff ratio, with 33" tires (285/75/16)
The calculator puts my RPMs at 70 MPH at 2,226
at 80 MPH at 2,544
at 90 MPH at 2,862
Below I've uploaded photos of my actual RPMs at those speeds (speed checked with GPS because my speedo is about 10% off).
Lo and behold my actual RPMs at 70.5 MPH are about 2,250 and at 80 MPH about 2,600 and at 90 MPH just below 3,000.
Seems pretty accurate to me.
Now just have to decide if the change should be made to the transfer case or to the differentials. Again, I'm perfectly fine with my low range driveability.