The Heavy Hitter QS165 60h V3 Billet Gear Box Cover is a precision-machined billet aluminum gearbox cover for the QS165 60h V3 motor, made by Heavy Hitter and sold here at GritShift. Integrated cooling fins, 2.695 fl oz of fluid against 2.265 fl oz for the OEM cover, black anodized, 1.37 lb, load tested past 13,000 lb.
Specs verified October 2026 against the live GritShift product page.
Specifications
| Material | Precision-machined billet aluminum |
|---|---|
| Finish | Black anodized |
| Weight | 1.37 lb |
| Cooling | Integrated cooling fins to manage gearbox fluid temperatures |
| Fluid capacity, Heavy Hitter cover | 2.695 fl oz |
| Fluid capacity, OEM cover | 2.265 fl oz |
| Load test | Withstood over 13,000 lb of force before reaching distortion |
| Fits | QS165 60h V3 motor |
| Hardware | Mounting bolts not included; reuse the OEM cover bolts or install new ones |
| Required for installation, not included | Mounting bolts (reused or new), output shaft seal 47x25x9 (reused or new) and anaerobic gasket maker |
What motors does the Heavy Hitter QS165 gear box cover fit?
- QS165 60h V3 motor
Why replace the OEM QS165 gearbox cover?
Heavy Hitter machines this cover with integrated cooling fins to manage gearbox fluid temperatures, and it holds slightly more oil: 2.695 fl oz against 2.265 fl oz for the OEM cover. Heavy Hitter is explicit that this is not a cosmetic upgrade. The fins and the extra fluid are there for a motor pushing real power through the drivetrain or being thrashed on a moto track, where the last thing you want is a weak link hiding behind the sprocket.
How strong is the billet gearbox cover?
During load testing the cover withstood over 13,000 lb of force before reaching distortion. For reference, Heavy Hitter puts the ultimate tensile strength of a typical 520 chain at around 6,000 to 9,000 lb, with a real-world fatigue limit much lower, so if something gives under extreme load the chain likely fails before the cover even thinks about bending. Hard landings and aggressive throttle spikes push a chain closer to its snap point; through those same shock loads the cover stays well below its bending threshold.
What do I need to install the QS165 gearbox cover?
Three items beyond the cover itself. The cover ships without mounting bolts, so you will reuse the OEM cover bolts or install new ones; you will need to reuse or install a new output shaft seal, size 47x25x9; and you will need anaerobic gasket maker to seal the cover to the case. Have all three on hand before you pull the OEM cover so the gearbox is not left open while you source parts.
Where can I buy the Heavy Hitter QS165 60h V3 Billet Gear Box Cover?
Right here. We sell the Heavy Hitter QS165 60h V3 Billet Gear Box Cover at GritShift, made by Heavy Hitter. Browse every Heavy Hitter part we carry in our Heavy Hitter collection.
