GM 7.5, 8.5 and Ford 8.8 axle info

Chevy

GM made two housings that came in these trucks, the 7.5/ 7.625 and the 8.5, both of which are ten bolts. The 7.5 has more of a squared of shape to the cover and straight axles tubes that measure 2 3/4" whereas the 8.5 uses a round cover and the axle tubes step down from 3" to 2 3/4" near the leaf pads.

2 wheel drive width from WMS to WMS is 54.5 inches
4 wheel drive width from WMS to WMS is 59-60 (depending who measures it) inches

S10 Rear end Ring Gear and Axle Sizes:
1983 to 1992 7.5" ring gear 26 spline axles
Available from 1988+ 7.625" ring gear 28 spline axles
Available from 1995 and up, 8.5" ring gear 30 spline axles, standard for 98+ ZR2's with rear discs


These are some of the axle RPO codes and should be the same for all GMs with either of these axles.

GU4=3.08
GU5=3.23
GU6=3.42
GT4=3.73
GT5=4.10
HC4=4.56

G80= locking differential

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Ford


All disk brake Explorer rear ends had 31 spline axles however there were a few drum brake rears that were 28 spline. Disc brakes was 95+
All Ranger other the the FX4 20002 and 2003 Lever II trim had 28 spline axles

Here's all the specs, measurements, and misc crap about the Explorer 8.8 you'll ever want to know.

Ford 8.8 specs:

Weight (complete assembly w/ brakes etc.): 174 lb.

Axle shaft strength: 6,500 (lb. ft.)

Drivers side Ford brake hose #:F5TZ-2282-A

Passenger side brake hose #: XL2Z-2282-AA

Bolt size (U-joint flange to yoke) is: 12 x 1.75 x 30 mm

Driveshaft Flange: Spicer Part Number 2-2-1379

Measurements:

O.D. of tubes: 3.250".

Tube thickness: .250" (some are .188”!)

Ring gear diameter: 8.800".

Ring gear bolts: 7/16" dia. (qty. 10).

Pinion diameter/splines: 1.625 / 30.

Axle shaft/splines: 1.320 / 31.

Rotor thickness (where it mounts to axle is .250").

Overall width 59.625". I have come up measurements online that say up to an inch wider, check yourself to be sure.

Hole diameter for ABS sensor in top of housing: .811".

Centerline of housing to C/L of pinion difference is 3.875" toward the P/S.

Explorer disks are non vented and measure 11 1/4" and are 5/8" thick.

Outside width of drum to drum.

Width Year Model
54.25 1983-2004 Chevy S10 2WD, GMC S15 2WD 7.5, 7.6, 8.5, 8.6
57.75 1962-1963 Chevy II/Nova 8.2 Dropout (nova only)
57.75 1964-1967 Chevy II/Nova 8.2 10 bolt or 12 Bolt
58.00 1978-1988 Chevy Malibu, Monte Carlo 7.5, 8.5 10 bolt
59.50 1968-1982 Corvette IRS
60.00 1955-1964 Chevy Car 8.2 Dropout
60.00 1967-1969 Camaro 8.2 10 bolt or 12 bolt
60.25 1968-1979 Chevy II/Nova 8.2, 7.5, 8.5 10 bolt or 12 bolt
60.50 1984-1995 Corvette IRS Dana 44 (manual trans) or Dana 36 (auto trans)
60.50 1964-1967 Chevelle 8.2 10 bolt or 12 bolt
62.00 1955-1959 Chevy Pickup 12 bolt truck
62.50 1968-1972 Chevelle 8.2, 8.5 10 bolt or 12 bolt
62.50 1970-1981 Camaro/Firebird 8.2, 8.5 10 bolt & 12 bolt