Front Differential
GM 7.2
Years Used on Astro / Safari Van: (1990 - 2005)
10 bolt front cover with 7.2" reverse cut ring gear.
The front differential in All Wheel Drive Astro/Safari vans is an independent front suspension design that shares many traits with those found in other GM compact and mid-size trucks.
Front Differential
GM 7.2
Astro / Safari Van: 1990 - 2005
Envoy: 2002 - 2005
S10 Blazer & Pickup: 1983 - 2002
Syclone: 1991 - 1991
Trailblazer: 2002 - 2005
Typhoon: 1992 - 1993
Differential Lockers
Lock-Right locker PT 1935
Differnetial Gears
3.08
3.42
3.73 all S10 ZR2 / Sonoma Highrider 1994-2005
4.11
4.56
Differential Internals
Image credit: Parts.com
Axle Seal Replacement
With the wheels on the ground unbolt the sway bar links (rusted ones may break)
Using solid points on the sub-frame, put the van on jack stands
Remove the wheel
Pull the brake caliper off the and hang from the upper A arm
Remove the rotor
Remove the bolt from the upper ball joint that holds the ABS wire
Dislodge the ABS wire from it's clips
Disconnect the outer tie rod from the steering knuckle (tie rod separator)
Disconnect the upper ball joint from the steering knuckle (sometimes a good wack with a hammer on the side of the knuckle, sometimes a pickle fork, try not to tear the boot)
Disconnect the lower shock mount
Let the lower A arm drop taking care not to let it hang by the ABS wire
Unbolt (1990-1996) or dislodge (1997-2005) the inner CV from the diff
Remove the axle shafts from the diff (crowbar behind CV mount surface (1990-1996) or crowbar placed in the outer clip groove (1997-2005), wiggle/pry out till it pops out)
Remove the old seals (2/3 jaw internal bearing puller with slide hammer)
Install new seals (bearing seal press, extra long handle made out of a 2x4 or similar helps)
Clean/smooth where the seal rides on the axle shaft (1990-1996) or CV (1997-2005)
Reverse to reassemble
Limited Slip & Locking Differentials
Front Differential
Limited Slip
- MFactory - helical type
- Bully Racing LLC - helical type
Locking
- Powertrax
Upgrade Research
GM 8.25
Aluminum front housing found in GM vehicles.
Uses 8.25" reverse cut ring gear