Main Shaft Bearing for Manual Transmission ⚙️

This OE-grade mainshaft support is the bearing that keeps your gearbox’s core alive. It holds the main shaft perfectly aligned, cuts friction, and preserves correct gear mesh. The result is quiet running, crisp shifts, and longer synchronizer life in daily driving and spirited use.

How it works

Hardened inner and outer races guide precision rolling elements inside an oil bath. The cage spaces them evenly, handling heavy radial load from gears and axial thrust from helical teeth. By keeping the shaft centered, it prevents wobble and wear across the whole transmission.

Why replacement is needed

Mileage, dirty fluid, or shock loads create play and pitting. Once clearance grows, gears lose perfect mesh, temperatures rise, and noise appears. Timely renewal restores factory tolerances and protects the cluster, input, and synchronizers.

What happens if it’s bad ⚠️

Expect high‑pitch whine with road speed, shifter buzz, hard engagement, pop‑out of gear, metal flakes in oil, and possible seal leaks. Continued driving can crack races, chip teeth, wipe synchros, or even seize the gearbox.

Tech tips ✅

Flush the case, inspect all bearings, set endplay/preload to spec, install new seals, use the correct GL‑4 oil, torque fasteners properly, and confirm shaft runout after assembly.

Compatibility

• Q40/G Sedan
• Q60/G Coupe
• Q60/G Convertible
• G35
• G37 Sedan