Timken DRK321MK Axle Differential Bearing and Seal Kit - Rear

Timken DRK321MK Differential Bearing Kit

Timken DRK321MK is a rear axle differential bearing and seal master kit for GM 8.5 in. ring gear applications. It brings together the bearings and seals needed for differential service on a wide range of Chevrolet, GMC, Buick, Oldsmobile, Pontiac, and Cadillac vehicles.

This part cross-references Monroe Shocks & Struts (e.g., RA321MK, SDK321MK) for the same application.

Key Features

• Rear axle differential bearing and seal master kit
• For 8.5 in. ring gear applications
• Timken DT Components rebuild kit
• Master kit version identified by the MK suffix
• Built for differential, transfer case, and transmission service applications within the DT Components line

Detailed Description

Timken DRK321MK is a DT Components master rebuild kit for rear differential service. It is built for GM vehicles using the 8.5 in. ring gear and is listed across many classic and light-duty truck, van, SUV, and passenger car applications. Common search terms for this part include rear axle differential bearing and seal kit for 8.5 in. ring gear, Timken DRK321MK, and GM 8.5 rear differential master kit.

Compatible vehicle coverage includes applications such as Chevrolet C1500, Chevrolet K1500, GMC K2500, Buick Roadmaster, and Pontiac Firebird, along with many other rear axle service applications from 1965 through 1996. If you are servicing a Chevrolet C1500 rear differential or a GMC Jimmy rear axle, this kit matches the listed master-kit applications.

Common Repair Uses

• Replacing worn differential bearings that cause noise or rough operation
• Addressing gear oil leaks at differential seals
• Restoring rear axle serviceability after teardown
• Repairing differential wear found during ring and pinion service
• Refreshing a high-mileage GM 8.5 in. rear axle assembly

Installation Notes and Tips

Confirm rear axle configuration and ring gear size before ordering. This kit is listed for rear position applications only, and fitment varies by year, make, and model. During installation, inspect the differential housing, bearings, races, and sealing surfaces for wear or damage before reassembly. Proper setup of bearing preload and gear pattern is critical after differential service.

Quality Assurance

Timken markets these rebuild kits through the DT Components line, which groups the bearings and seals needed to complete differential service work. The MK suffix identifies this as a master kit version.