Is there an easy way to physically verify wether 4.10 gears are installed? Are the ratios stamped on the diff's or tagged?

I will be picking up my JK shortly and I want to make sure they got the order right after some of the other problems I have heard of on here with incorrect options from the factory.

thanks

 

As far as I know, no one has seen an id tag on a JK differential.

Chock the front tires, fore and aft.
Put the transmission in neutral.
Emergency brake off.
Jack the left rear tire off the ground.
Put a jack stand under the frame, just in case the jack fails (had to add this).
Put an index mark on the aft end of the drive shaft, visible from the left rear wheel.
Put an index mark on the left rear tire at the 6 o'clock position.
Rotate the left rear tire 2 complete revolutions while counting how many times the index mark on the drive shaft passes its original position.
That number will be your axle ratio.
Remove jack stand and lower jack.
Put transmission in gear or Park, apply emergency brake.
Remove chocks.
If you have limited slip, jack up both rear wheels and rotate one revolution, making sure both tires rotate equally.

If the drive shaft rotated almost 3¼ turns, you have 3.21
If the drive shaft rotated almost 3¾ turns, you have 3.73
If the drive shaft rotated a little over 4 turns, you have 4.10
If the drive shaft rotated 4½ turns, you have 4.56
If the drive shaft rotated a little under 5 turns, you have 4.88
If the drive shaft rotated a little over 5 turns, you have 5.13

 

Just call the dealership with your vin#

 

I will check it as soon as I get home. I wanted to have a simple way to check on the lot before I sign the papers.

Thanks

 

Thats the point, I don't always trust the dealer. I want to verify personally. I know more than the dealer about jeeps and vehicles in general.