FAST Manual Transmissions — 8 / 12 / 16-Speed

FAST

Specifications

Source: FAST official product pages (fast-gear.com manual-transmission series; chinafastgear.com English catalog). Model selection depends on engine rating and vehicle duty.

Product family	FAST 8JS / 12JSD / 16JSD series manual transmissions
Architecture	Twin-countershaft design in main box and auxiliary box
8JS series input torque	850–1250 N·m (models 8JS85 to 8JS125), 8 speeds, 180–270 kg
12JSD series input torque	1600–3000 N·m (12JSD160 / 180 / C12JSDQXL180T–320T), 12 speeds, 312–375 kg
16JSDX series input torque	16JSDX200T / 16JSDX240T at 2000 / 2400 N·m, 16 speeds
Ratio spread (16JSDX240T)	16.693 : 1.000 overall range
Max input speed	2600 rpm
Typical application	Heavy and medium commercial trucks, tractors, vocational and construction vehicles

Key features

• Twin-countershaft architecture splits torque over two parallel shafts — proven in FAST's long-running heavy-truck program.
• 8 to 16 speeds across the family, so the same installation envelope covers medium-duty 850 N·m units and 3000 N·m long-haul tractors.
• 16-speed top units use a 2×4×2 layout with helical auxiliary gearing and short-stroke synchronizers for quieter shifting.
• Common clutch housing and PTO interfaces with Weichai diesel engines, including the WP10H and WP13 ratings.
• Spare parts and service support follow the FAST commercial-vehicle parts network.

Applications

The 8JS line suits medium-duty trucks and buses; the 12JSD line covers the heavy long-haul band; the 16JSDX200T/240T is the top-grade manual for the heaviest tractor and vocational duties where a wide ratio spread matters.

Customization

Available on request: ratio selection and PTO position, clutch and flywheel-housing matching to the chosen Weichai engine, output-shaft and drive-flange options, retarder-ready variants, and export parts lists with workshop documentation.

Product Description

The FAST Manual Transmissions — 8 / 12 / 16-Speed is a FAST (Fast Gear) transmission built for heavy commercial and off-highway applications. It delivers smooth gear shifts, high torque capacity and long service life in mining trucks, dumpers, concrete mixers and special-purpose vehicles.

SDHI exports this transmission as a standalone component or matched with Weichai engines and HanDe axles as a complete powertrain package for truck OEMs, mining fleets and conversion customers. We provide installation drawings, English technical manuals and global spare parts supply.

Why Choose FAST Manual Transmissions — 8 / 12 / 16-Speed

• High torque capacity for mining duty
• Synchronized / constant-mesh options
• Matched with Weichai + HanDe driveline
• Service and overhaul kits available
• Global parts and technical support