leeboy

Im about to buy new gears (3:54's), i believe i have 4:10's. ( 2000 rpm at 60 MPH with Automatic) I looked in the Glove compartment, but didnt see a tag. Is there anywhere's else i could check just to be 100% sure i have 4:10's?

Haulin_in_Dixie

Under the hood at the front. There is a sticker there. If not, jack up the back, put a chalk mark on the tires and on the drive shaft. Have someone turn the tires. If it is limited slip you will only have to turn one wheel or if it is open gearing you will have to turn both wheels not necessarily at the same time. turn the rear wheels one complete turn, the drive shaft will turn 3 and 1/2 turns if 3.55 or a hare over 4 if it is 4.10.

BigIron70

Gear ratio is stamped on gears. If your 4X4 you need to change the front gears to match or you'll tear up the transfercase.

mopar-or-no-car

I believe there is a tag on the diff. Also you could take your vin number to a dealer and have them print off a spec sheet for your truck.

tx_2500

Yeah you have a 4.10 judging from mph/rpm

Haulin_in_Dixie

Unless you can find the numbers on the end of the pinion shaft, counting the turns is the only sure way.

Shovelhead

Check inside the glovebox.
There should be a build sticker on the inside of the glovebox door,

WestTN

If there is no tag that could mean the gear has been changed. In that event the dealer would be wrong. Just do the driveshaft and wheel check above, and you will have the truth.

leeboy

yep........its definately 4:10's by the wheel turning...thanks everyone

Joe Diesel

heres a calculator you could've used

http://www.competitiondiesel.com/Phil/bg/