My question is what is the easiest way to find out what gears I have? I also have a rear locker and electronic disco swaybar from the factory. My thoughts are whoever had my jeep before me order these from the factory like this, so I think I have 4.10 cause I have 33 and it only threw off my speedometer by a 2 mph

 

You can email your vin to jeep/chrysler and they will send you a build sheet in your jeep.

 

Copied from another thread;
Jack up rear end. Put Jeep in neutral. Turn one of the rear wheels while looking at the drive shaft. Count the number of turns for the drive shaft for every turn of rear wheel.

If DS turns slightly over 3 turns, then you have 3.21

If DS turns nearly 4 turns, then you have 3.73

If DS turns slightly more than 4 turns, then you have 4.10


Or,
I sent for a copy of my build sheet and got an email back in about 24 hrs; Chrysler Link
Click the "I need CUSTOMER ASSISTANCE" then send them an email including your VIN and you get the complete build sheet for your Jeep.
.

 

what he said above only, you don't even need to jack your jeep up. just make a mark on your drive shaft and one on your tire and roll it forward or back in neutral and start counting.

 

Personally, I think the easiest way is to measure a tire and look at the gearing chart.