I bought my 2002 RAM 2500 CTD in March but the dealer I purchased it from didn't know what gearing it had in the differential. What RPM should I be seeing at 60MPH with the automatic transmission in overdrive and the truck unloaded on a level road with the choice of gearing offered that model year? There have been no modifications made to the drive train.

 

I can't help you with automatic trans rpms, but did you look in the glove box? There should be a tag there that gives the diff info. That is where it is on my truck. On some of the older trucks, Its on the bottom of the hood when you raise it, right in the center. If nothing in either one of those places, look for the metal tag under one of the diff cover bolts, should be there also.

 

That's right where is was. Thanks.