Having a problem with GM 12 bolt rear end?  We offer a complete line of rear end parts for the GM 8.875" commonly referred to as the 12 Bolt truck differential, this differential was utalized GM used this very popular differential in there full size Chevrolet trucks starting in 1964 to 1982. Our inventory includes ring gear and pinion sets, including aftermarket and OE gear sets. We are able to supply axles, bearing overhaul kits, carriers, cases, spider and side gears.

The Positraction units we offer include Lockright, no-Slip Powertrax, Auburn, Eaton Posi, Detroit Lockers and TrueTrac . We are a Dana Spice volume distributor and offer a complete line or ring gear and pinions to the large Dana 80 differential. In addition to the Dana Spicer line we quality offer differential products.

Specifications are provided below to assist you in the identification and setup as well as torque spec's for your Chevy or GM 8.875" differential.

GM 8.875" 12 Bolt Applications 1/2 & 3/4 ton trucks Model Year G20, G25 64-82 G10, G15 64-81 K10, K15, C10, C15 64-82 What differential ratio do you have? Need information on how to setup ring and pinion backlash Purchase your parts @ drivetrain.com and receive telephone access to experienced differential technician to assist you with installation, we help you solve the problem.

12 Bolt Truck Specifications 11-1/2" 12 HOLES Irregular Gasket Pattern RG Diameter 8.875" 12 3/8" X 24 RH Threaded Bolts PINION Diameter 1.438", 30 Spline CASE: 2.56 -2.73, 2.76-3.42 & 3.73 Numerically Higher 8620 Material Heat-Treated Assembly Specifications: Cover Bolt Ft. Lbs. 20 Pinion Brg. Preload In. Lbs 24-25 Pinion Brg. Preload In. Lbs 10-15 Used Ring Gear Backlash .005-.009 Ring Gear Bolt to case Ft. Lbs. 90 Side Brg. Caps Ft. Lbs. 60

Chevrolet GM 8.875" 12 Bolt Truck Ring and Pinion Products

GM 8.875" 12 Bolt Differential Ring Gear and Pinion Set			Quaility Gears provide guaranteed performance		Order our high performance synthetic oil and friction additive combo kit at time of order for ring and pinion or bearing overhaul kit and pay only $49.95 plus S&H, a $54.00 value. See other Red Line Oil Products that we recommend.
Part Number	OE Number	Ratio	Teeth	Price
GM12-308		3.08	40-13	$214.94
GM12-342		3.42	41-12	$214.94
GM12-373		3.73	41-11	$214.94
GM12-373X*		3.73	41-11	$214.94
GM12-411		4.11	39-9	$214.94
GM12-411X*		4.11	37-9	$214.94
GM12-456		4.56	41-9	$214.94
*Fits 2.76 go 3.42 Case