Gear ratio has been changed?

[rfmodulator]

1997 1500 4x4 5.2 auto

DGB - STD DUTY 4SPD AUTO TRANS
DMD - 3.5 AXLE RATIO

285/75R16, speedometer is calibrated correctly with GPS, or very dang close.

RPM is ~1625 @ 60MPH in OD

An online calculator I used says it should be in the 3.80 to 3.90 range, based on 0.69:1 OD, and 32.8 inch tires.

None of this data is scientifically validated, but if it's anywhere close then the factory 3.50s must have been swapped, right?

 

[rfmodulator]

RPM is ~2250 @ 60MPH in 3rd

 

[GTyankee]

video to determine differential ratio with a open rear end

Easiest Way to Determine Rear End Gear Ratio on a Open Differential

In this episode of Budget Build Garage Nick explains and demonstrates the easiest way to determine rear end gear ratio on a open differential. The best part ...

www.youtube.com

 

[rfmodulator]

Thank you @GTyankee, I will give that a shot later this week.

 

[GTyankee]

Limited Slip differentials are done by jacking up the rear differential also & the tape is applied the same way, but the counting method is different
1 full rotation of the tire = how many turns of the drive shaft

 

[rfmodulator]

I'm pretty sure it's an open diff, there's nothing on the tag that says otherwise. But I'll verify when I jack it up.

Also...

DHK - TRANSFER CASE 231 -H.D.

This would be a 1:1 Hi range, right? ...I can't imagine it would be anything else.

 

[dapepper9]

You have 3.55s if you're running about 15-1600 in OD at 60.