Rear end info-
These rears will work but wont hold up to serious power...The Ford 8.8 rear out of a 96-2001 ford explorer are the most affordable option for 350+ hp engines.If you are dead set on using the s10 rears here is some very useful info I found.... 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 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
Engine/Tranny/RearEnd/Gear Ratio Combos
|S10 Pickups |
1995 s10 2wd 8.5 rear, (LB4,L35,M30,GU6)
1995-1997 s10 2wd 8.5 rear, (LN2,M30,GT5)
1996-1999 s10 2wd 8.5 rear, (L35,M50,GU4,G80)
2000-2002 s10 2wd 8.5 rear, (M50,GU4,G80)
2003 s10 2wd 8.5 rear, (LU3,M50,GU4,G80)
1995-1997 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
1998-1999 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
2000-2001 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
2001-2004 s10 blazer 2wd 8.5 rear, (M50,GU6,G80)
2003-2005 s10 blazer 2wd 8.5 rear, (M50,GU6)
So... for example if you are looking for a 8.5 rear end with 3.42 gears and posi, you can find it in a v6 blazer 2wd with a manual 5spd trans...
There are also 8.5 rear ends in 4x4 s10's but i did not list them... Hope this helps you find the rear end you want.
Axle Codes/Engine Codes
These are some of the axle RPO codes and should be the same for all GMs with either of these axles.(these codes are located in the glove box on s10)
G80= locking differential
LB4- 4.3 V6 TBI
LN2- 2.2l 4cyl MFI
LU3- 4.3 V6
L35- 4.3 V6 CPI
M30- Auto 4 speed trans
5 SPEED trans
This subject comes up often enough I thought I'd post this service bulletin
There's a lot of conflicting info about whether or not to use a posi or limited-slip additive to the gear oil when filling a G80 (Eaton Gov-Loc) differential in a GM truck.
Much of the confusion likely comes from the fact that the G80 RPO code is also used to indicate posi or limited slip differentials in car applications, but in trucks it is the Eaton Gov-Loc. It doesn't help when someone goes to Eaton's site and finds statements like:
"What type of lubricant and limited slip additive should I use with my newly purchased Eaton Limited Slip Differential? Eaton strongly recommends utilizing an API-GL5 approved Mineral-Based 80W-90 Axle Lubricant and one 4-oz bottle of Limited Slip Additive (GM or Ford)."
Note that the Eaton Gov-Loc is NOT a limited slip; the information in the above paragraph does not apply to the Eaton unit used by GM for the trucks!
Here's the service bulletin from GM about the proper lubricant and use of additives (I added the bold and underline):
- GM Said:
SUBJECT: LOCKING DIFFERENTIAL (G80) LUBRICANT - (SERVICE INFORMATION)
VEHICLES AFFECTED: ALL LIGHT TRUCKS EQUIPPED WITH G80 REAR AXLE ALL YEARS
Some light duty trucks equipped with locking rear axles (G80) may exhibit rear axle chatter, especially when turning a corner from a stop.
This condition of alternate engagement and disengagement of clutches in differential assembly is usually caused by contaminated axle lubricant.
To correct this condition, drain and refill the rear axle with SAE 80W-90 GL5 (P/N 10950849).
The use of any additive in locking rear axles (G80) is not recommended. Rear axle additives are designed for use in limited slip differentials which are normally installed in cars. All light duty trucks equipped with RPO G80 make use of a locking differential and the use of additives will delay the engagement of the locking mechanism and may decrease axle life.
VEHICLES/COMPONENTS INVOLVED: ------------------------- ---- Some light duty trucks equipped with locking rear axles, RPO G80.
SERVICE PARTS INFORMATION:
Part Number Description ----------- ------------------ 10950849 Lubricant, Rear Axle (1 litre)