Slat set Power Shuttle

Set consists of 5 inner and 5 outer slats
Made in Italy

Tractor creeps forward or backward in neutral position
The snap ring holding the lubricating seal on the clutch shaft slips or the seal is damaged. This can cause lubricating oil to fill the clutch housing and cause the tractor to creep.

NOTE: This information applies only to tractors with a Power Shuttle transmission. For clarification, see the attached drawing.

When a properly operating powershuttle transmission is set in neutral, the only parts that rotate inside the transmission are the outer drive hub clutch A (forward) (part number 5181843) and the centre drive hub clutch B (reverse). When shifting to neutral, no low pressure system oil is sent to the pistons of either clutch A or clutch B. Both pistons rest in the home position. In the home position, the clutch pistons interrupt the lubricating oil supply port, which would otherwise flood the inside of the clutch. When the piston moves forward to the engaged position, the lubricating oil supply port is opened and oil flows into the inside of the clutch.

Lubricating oil is interrupted to both clutches at neutral position to prevent gear creep. When lubricating oil fills up the inside of the clutch when shifting to neutral, the clutch engages and drives the tractor. The degree of transmission creep is sometimes worse at cold oil temperature because the oil viscosity is heavier when cold.

If any of the seals or gaskets listed in the attached drawing are damaged or missing, lubricating oil will fill the inside of the clutch and cause the clutch to engage.

It is difficult to determine if a lubricating oil seal inside the transmission is leaking and causing transmission creep before the forward and reverse clutches are disassembled. Any leak is too small to be detected with a pressure gauge in the lubrication circuit. The oil pressure in this circuit is regulated to about 3.4 bar (50 psi) and has plenty of capacity to withstand a leaking seal without pressure drop.

To determine if a leaking lubricating oil seal is causing transmission creep, before disassembling the transmission, perform the following test.

A. Disconnect the lube oil supply line (part number 47134941) that runs from the hydraulic oil cooler back to the powershuttle control valve.

B. Make a hose that connects to the open end of the lubrication supply line and route the hose to the rear of the tractor into the hydraulic oil fill line (part number 5180869).

C. With the manufactured hose secured at both ends, start the engine and let it idle. Run the engine for several minutes to allow any residual lubricating oil to be thrown out of the couplings.

D. With the engine at idle and the gear change lever in neutral, check for transmission creep. If creep is no longer present, then the test confirms that lubricating oil is leaking inside the clutch and causing transmission creep at idle.

E. Follow the procedures in the repair manual for removing, repairing and reassembling the clutch.

NOTE: Do not drive the tractor with the lubrication circuit disconnected. This will cause damage to the transmission. The lubrication circuit is disconnected only for tests at standstill.

If the inner clutch hub bearing 'A' (part number 28042510) fails, it will not create excessive resistance and may also cause transmission creep in the forward direction.

If the drive plates or separator plates of clutch A or B (part number 5185943) distort, this will also cause gear creep.