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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

Part ID
Part Name
Compatible Years
1 Axle 1990-1996
1997-1998
1999-2002
2003-2005
2 Axle Shaft Right 1990-1996
1997-2005
3 Deflector 1990-1996
1997-2004
2005
4 Seal 1990-1996
1997-2005
5 Output Shaft Bearing 1990-1996
1997-2005
6 Output Shaft Tube Assy 1990-1996
1997-2005
7 Ring 1990-2005
8 Bolt 1990-2005
9 Housing 1990-1996
1997-2005
10 Insert 1990-2005
11 Sleeve
12 Side Bearings 1990-2005
13 Case 1990-2005
14 Gear Kit 3.42
Gear Kit 3.73
1990-2005
1990-2004
15 Axle Bearings 1990-1996
1997-2005
16 Bushings 1990-2005
17 Shim Kit 1990-2005
18 Inner Pinion Bearing 1990-2005
19 Pinion Spacer 1990-2005
20 Outer Pinion Bearing 1990-2005
21 Deflector 1990-2005
22 Companion Flange 1990-1999
2000-2005
23 Shaft 1990-2005
24 Washers 1990-2005
25 Gear Kit 1990-2005
26 Washers 1990-2005
27 Cover 1990-1996
1997-2005
28 Axle Shaft Left
1990-1996
1997-2005
Source:   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


Upgrade Research

GM 8.25
Aluminum front housing found in GM vehicles.
Uses 8.25" reverse cut ring gear






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