When a vehicle is negotiating a corner, the outside wheel has to travel a greater distance than the inside wheel. Therefore the outside wheel must turn faster than the inside wheel. The differential is the device within an axle assembly that differentiates the wheel speed between the two wheels. The differential also transmits the power from the ring gear to the axle shafts and determines how much power is delivered to each axle shaft.
The conventional differential transmits power through a set of spider and side gears to the axle shafts. Power is normally equal to both shafts. But, if one wheel slips, the other wheel receives very little power. This differential is fitted as standard equipment on most vehicles due to its suitability for everyday driving on paved roads.
While similar to conventional differentials, limited slip type differentials add a friction medium to the assembly to maintain equal power to both axles even if one tire begins to slip. When load is applied to the differential, the friction plates are also loaded, causing a good positive power flow to both tires.
This type of differential transmits power through a set of automatic locking dog clutches. This automatic locking action keeps both axles locked together except while cornering when they unlock to allow normal differentation. Severe off-roading demands this type of differential.
Manual locking differentials offer the driver the option of choosing between a conventional or a fully locked differential at the touch of a button (cable, etc). This provides versatility in a vehicle that will be used in both street and extreme off-road situations.
The pattern is spread evenly over tooth's profile with concentration nearer toe than heel.
The pattern is concentrated just up from the toe covering 1/3 to 1/2 of the tooth.
The pattern is concentrated at the crown of the drive gear tooth.
How to fix: Move the pinion deeper towards the differential carrier (add pinion shim).
The pattern is concentrated in the root of the drive gear tooth.
How to fix: Move the pinion out away from the differential carrier (subtract pinion shim).
The pattern is concentrated off the heel end of the drive gear tooth.
How to fix: Move the ring gear closer to the pinion (decrease backlash) while maintaining minimum backlash.
The pattern is concentrated off the toe end of the drive gear tooth.
How to fix: Move the ring gear away from the pinion (increase backlash) while maintaining minimum backlash.
When you change your tire size you need to make sure you have the right gearing to get optimal fuel economy and power. A good way to calculate this is to multiply .12 by your Jeeps tire diameter (example: .12 X 38" = 4.56). Alloy USA has made an easy-to-read chart to help you decide what is the best gearing for your Jeep. The three distinct colors below can help you decide what is the right gearing for you...
These calculations are assuming a manual transmission at 65 MPH with a gear ratio of 1:1. If you drive an automatic your RPMs will be slightly higher, and if you have overdrive your RPMs will be slightly lower.
Here's a formula you can use to calculate your vehicle's tire diameter:
(cross section width x 0.aspect ratio x 2 ÷ 25.4) + wheel diameter = overall tire diameter
For Example: 235/45ZR-1 (235 x 0.45 x 2 ÷ 25.4) + 17 = 25.327"
And here's a formula that you can use to calculate your vehicle's rear axle gear ratio:
ring gear tooth count ÷ pinion gear tooth count = gear ratio
For example: 41-tooth ring gear ÷ 10-tooth pinion gear = 4.10
All new ring & pinion sets require a brief break-in period in order to ensure long life and quiet operation. The following break-in procedure is recommended before applying a heavy load and/or constant usage.