goin to 4.56
Senior Member
Joined: Jul 2007
Posts: 175
Likes: 0
From: North Port, FL
The install is a bolt-on, but you do need to pay attention to pinion bearing pre-load, backlash, drive pattern and carrier bearing pre-load.
I have done about 20+ gear swaps on 8.8" rearend mustangs, and just do the 9.75" and the 8.8" IFS in my 2002.
90% of the time, I have always been able to use the same shim on the pinion and the differential carrier shims.
On my 02, the Rear worked out perfect on the backlash, drive pattern and carrier bearing preloads by using the shim on the factory 3.55's and then Swapped the differential carrier shims (IE, the passenger went to the driver side, and the driver side went on the passenger side of the differential).
I did the same thing on the front 8.8" IFS and it resulted in a somewhat tight backlash setting (specs are .006" to .010", mine was .003"), but since I didn't have any differential carrier shims, and rarely use my 4 wheel drive (this will probly change now though), I left it as is.
The one thing I was suggested to do after the re-gear and 500 mile break-in period, was to install an aftermarket differential cover on the rear axle that increased the fluid capacity. The increased fluid capacity helps keep the diff oil temperature lower, so the oil doesn't get to hot and start braking down.
Be sure to have access to an air impact gun to crush the new crush sleeves, and atleast a 2 ton arbor press for removing/installing the pinion and carrier bearings.
I have done about 20+ gear swaps on 8.8" rearend mustangs, and just do the 9.75" and the 8.8" IFS in my 2002.
90% of the time, I have always been able to use the same shim on the pinion and the differential carrier shims.
On my 02, the Rear worked out perfect on the backlash, drive pattern and carrier bearing preloads by using the shim on the factory 3.55's and then Swapped the differential carrier shims (IE, the passenger went to the driver side, and the driver side went on the passenger side of the differential).
I did the same thing on the front 8.8" IFS and it resulted in a somewhat tight backlash setting (specs are .006" to .010", mine was .003"), but since I didn't have any differential carrier shims, and rarely use my 4 wheel drive (this will probly change now though), I left it as is.
The one thing I was suggested to do after the re-gear and 500 mile break-in period, was to install an aftermarket differential cover on the rear axle that increased the fluid capacity. The increased fluid capacity helps keep the diff oil temperature lower, so the oil doesn't get to hot and start braking down.
Be sure to have access to an air impact gun to crush the new crush sleeves, and atleast a 2 ton arbor press for removing/installing the pinion and carrier bearings.