HYDRO-GEAR BDP

The Hydro Gear pump part number BDP-21L is driven by the engine, and the motor is connected to the differential .It consists of variable volume, reversible swashplate, and axial piston pump.

The pump inlet is connected to the transmission housing, so the pump can make up for any oil that is lost. The make up oil is taken from the transmission housing through an oil filter screen. The motor speed is then controlled by the pump rpm and the angle of the swash plate, 51048.

The BDP-10A hydro gear pump turns in the same direction at all times. The pump motor is capable of turning in both directions. Reversing pump swash plate angle, which then in returns reverses the flow of oil being pumped to the motor, reverses direction of motor rotation. 

When trouble shooting your Hydro Gear Pump BDP-10L checks all the most obvious places first. For example lack of drive in one direction could be caused by: swash plate being restricted in one direction or check valve not seating. Lack of drive in both directions: drive belt slipping or breaking, oil level low, filter screen plugged, valve stuck open or leaking, or broken control linkage.

To overhaul your transmission, first remove your control arm. Unbolt oil reservoir 2003081 and then separate cover from housing. Remove check valves and pull out oil seals. Lay housing over and pull out cylinder block, 70081, and your shaft 2003020,         will slide out.

Inspect pistons and cylinder bores for any excessive damage. You can only service your pump and motor cylinder as complete assemblies. Always check your cylinder blocks for wear, scoring or scratches. Coat parts with oil during reassembly. Make sure the pistons are returned to their original bores in cylinder blocks.

HYDRO-GEAR BDU

The Hydro Gear pump part number BDU-21L is driven by the engine, and the motor is connected to the differential .It consists of variable volume, reversible swashplate,51048, and axial piston pump.

The BDU-10L hydro gear pump turns in the same direction at all times. The pump motor is capable of turning in both directions. Reversing pump swash plate angle, which then in returns reverses the flow of oil being pumped to the motor, reverses direction of motor rotation. 

The motor speed is controlled by the pump rpm and the angle of the swash plate. The pump inlet is connected to the transmission housing, so the pump can make up for any oil that is lost. The make up oil is taken from the transmission housing through an oil filter screen.

To overhaul your transmission, first remove your control arm. Unbolt oil reservoir and then separate cover from housing. Remove check valves and pull out oil seals, 44761. Lay housing, 2513003 over and pull out cylinder block, and your shaft 2003032, will slide out. Inspect pistons and cylinder bores for any excessive damage. Always check your cylinder blocks for wear, scoring or scratches

. When trouble shooting your Hydro Gear Pump BDU-10S checks all the most obvious places first. For example, lack of drive in both directions: drive belt slipping or breaking, oil level low, filter screen plugged, valve stuck open or leaking, or broken control linkage. lack of drive in one direction could be caused by: swash plate being restricted in one direction or check valve not seating            .

The control handle, 51680, has three positions, forward, reverse and neutral, which all effect the swash plate position. The acceleration control  and valves  protect circuits from extra pressure. They also keep the unit from jerking.