CHRYSLER
PROBLEM: CHRYSLER: 9.25", 12 Bolt Cover, 4.56 and Higher.
I bought 4.56 gears for my 1/2 ton pickup, but I cannot get the cross pin into my carrier.
SOLUTION: It does not matter whose gears you use. You will need to modify your cross pin to use a 4.56 or higher gear in your vehicle. This applies for open differential, Auburn and Eaton differentials. The pin will need to be cut at an angle opposite the bolt hole. Because every manufacturer is different, no measurement is provided.
FORD
PROBLEM: FORD: 7.5", 10 Bolt
I bought 4.56 gears for my early fox body (pre-1986) and I cannot get the cross pin into the carrier.
SOLUTION:
It does not matter whose gears you use. You will need to modify your cross pin to use a 4.56 or higher gear in your vehicle. This applies for open differential, Auburn and Eaton differentials. The pin will need to be cut at an angle opposite the bolt hole. Because every manufacturer is different, no measurement is provided.
PROBLEM: FORD: 8"
I bought an Auburn for my early Ford, but the inner diameter of my carrier bearings is too small.
SOLUTION: When replacing a stock carrier with an Auburn, you must change the carrier bearings to LM102911 and LM102949. You will need 2 of each. Install kits are available.
PROBLEM: FORD: 9" Deep Ratio and Motive AX Gears.
My gears look melted! They must be soft!
SOLUTION: On the deep ratios and Motive AX gears we recommend that you use a Dayton style pinion support, solid pinion spacer and baffle in the outter axle tube. Without these 3 changes your gears and bearings will get too hot and will cause the gears to anneal. Annealing will destroy the heat treatment applied to your gears at the factory and make them soft. This is why the gears will appear to have "melted" to some degree.
GENERAL MOTORS
PROBLEM: GM: 7.5"/7.6", Bolt Differential, 4.56 and Higher.
I bought 4.56 gears for my F-Body and I cannot get the cross pin into the carrier.
SOLUTION: It does not matter whose gears you use. You will need to modify your cross pin to use a 4.56 or higher gear in your vehicle. This applies for open differential, Auburn, Eaton, and Gov lock differentials*. The pin will need to be cut at an angle opposite the bolt hole. Because every manufacturer is different, no measurement is provided.
* If your F-Body is a SS or WS6, you have a Torsen differential. This uses a block and paddle system that cannot be modified. However, SLP has a block and paddle kit that will allow you to use a 4.56 and numerically higher ring and pinion.