This maintenance manual (MM5A) provides service and repair instructions for AxleTech Single Reduction Differential Carriers, specifically models RS-140, RS-145, RS-160, and RS-180. These carriers may be equipped with a Driver-Controlled Main Differential Lock (DCDL), which uses a hydraulic shift assembly to lock the axle shafts together for maximum traction .

1. Key Technical Specifications

The manual establishes strict adjustment parameters required during assembly:

Pinion Bearing Preload: Controlled by a spacer between bearings. New bearings require 15-25 lb-in (1.7-2.8 N·m), while used bearings in good condition require 5-25 lb-in (1.7-2.8 N·m).
Differential Bearing Preload: The standard specification is 15-35 lb-in (1.7-3.9 N·m). It can also be measured by expansion between bearing caps: 0.002-0.009-inch (0.05-0.229 mm) for RS-140/145/160 models and 0.006-0.013-inch (0.15-0.33 mm) for RS-180 models.
Ring Gear Backlash: For gears with a pitch diameter of 17 inches or larger, the range is 0.010-0.020-inch (0.25-0.51 mm), with a nominal setting of 0.015-inch (0.38 mm) for new sets.
Runout and Resistance: Maximum allowable ring gear runout is 0.008-inch (0.20 mm). The maximum rotating resistance for differential gears is 50 lb-ft (68 N·m).

2. Core Assembly Procedures

Pinion Depth Adjustment: Controlled by shims between the bearing cage and carrier. Technicians must calculate new shim thickness based on previous measurements and the Pinion Cone (PC) variation numbers die-cut on the gears.
Ring Gear Installation: Ring gears must be heated in water to 160°F-180°F (71°C-82°C) for 10 to 15 minutes before installation. They should never be pressed on cold, as this can damage the case half.
Matched Sets: Drive pinions and ring gears are only available as matched sets and must always be replaced together .

3. Lubrication and Maintenance

Oil Quality: Use API GL-5 hypoid gear oil. Viscosity should be selected based on ambient operating temperatures.
Change Intervals: Requirements vary by vocation; for instance, heavy-haul vocations require petroleum-based oil changes every 25,000 miles or annually. Sump temperatures must never exceed 250°F (121°C).

4. Safety and Towing

Carrier Handling: Before removing or installing a DCDL-equipped carrier, the lock must be manually engaged and held using a manual engaging capscrew to ensure necessary clearance from the axle housing .
Towing Requirements: Axle shafts must be removed before towing the vehicle with the drive wheels on the ground to prevent internal component damage .