Most TMP 12000 units are designed for right-hand rotation engines. Note that direct-drive models turn the propeller in the same direction as the engine, while reduction boxes may vary based on the number of pinions used. Critical Maintenance and Assembly Components
The gearbox is typically attached to the engine bell housing by internal nuts. You must remove the gearbox and bell housing as a single unit.
If the 8-bush input is seized due to rust, experts at Thamesway Marine Products suggest cutting a small access hole in the housing to apply lubricant and leverage the flywheel directly. 2. Inspection for Wear tmp gearbox workshop manual top
Before beginning any workshop repairs, confirm the specific model from the serial plate located on top of the gearbox.
Check the pressure plate face and gears for ovality. Excessive wear here leads to a "flicking" pressure gauge or total loss of drive. Most TMP 12000 units are designed for right-hand
Since the bell housing often carries the rear engine mounts, ensure the engine is properly supported before unbolting.
Maintaining a marine transmission like the series requires technical precision and a deep understanding of its unique hydraulic and mechanical architecture. These gearboxes, originally produced by manufacturers like Thames Marine Propulsion and Henry Meadows, are heavy-duty units that demand specific procedures for overhaul and service. Essential Technical Specifications You must remove the gearbox and bell housing
A full overhaul requires specific replacement parts to ensure the integrity of the hydraulic seals and mechanical drive. Component Type Part Number / Requirement Seals the output shaft for direct drive units. Gasket Kit Includes essential O-rings for pressure integrity. Brake Pad Neutral brake pad for stopping shaft rotation. Oil Filter TM 12009 / 12773 Models differ between MK II and MK IV versions. Step-by-Step Workshop Procedures 1. Removal and Disengagement
Use only SAE #30 engine oil . Avoid multi-grade oils (e.g., 10W40), as they can negatively impact the coefficient of friction and cause clutch slippage.
A rearward movement of approximately 2.0 inches is usually required to clear the input shaft. For Mercedes-based installations, this may increase to 6.0 inches.