Hi all,
JK 2.8 CRD Sport 2011,
how do I recognize a front axle dana 186 MM with 3.21,the one with 3.73?
there is a part number on the front axle ?
or by ring and pinion ?
thank you

Giacomo

 

Call or e-mail Jeep and request your buildsheet for the vehicle. That'll tell you evrything and then some!

 

Thank you BossHog,
I know that I have 3.21 gear ratio,but wanted to know how to recognize an front axle with 3.73.
externally are the same or different ?
thank you

Giacomo

 

Externally the only way to do this is manually counting rotations of the tire vs. pinion.

Mark the pinion and pumpkin at 12 o'clock with a line to count off of.

Lift the front of the vehicle and rotate both tires one revolution (Or you could rotate one tire, just make sure the other is moving along with it, you dont want the differential to throw the count off.)

As you rotate the tires, have someone count how many revolutions the pinion makes. 3.21 should end up right around the three o'clock position, 3.75 should be right around the 9 o'clock position.

Pretty simple. Same method applies if the axle is already out of the vehicle.

 

Thank you Blakspire,
and wanting to do a check inside the differential ?
you know the number of ring and pinion teeth?

Giacomo

 

Nah,

All I know is the method I described. I guess, common sense would say count the teeth on the pinnion gear(pg) and count the teeth on the ring gear (rg). rg/pg=axle ratio

 

number of ring gear teeth divided by number of pinion gear teeth = axle gear ratio

example: 41 ring gear teeth divided by 10 pinion gear teeth = 4.10 gear ratio

You can also count the number of times the drive shaft turns with each revolution of the tire.

example: one tire revolution causes the drive shaft shaft to turn slightly less than 3 1/4 turns = 3.21 gears

 

Thank you all,
now another question
I would like to know if the front dana 30 axle housing is possible to fit the case kit differential with 3.21 ratio than that with 3.73 ratio
thank you

Giacomo