T25 Syncro Diff Lock Valve

Replacement vacuum control valve for the differential lock system fitted to Volkswagen T25/T3 Syncro models.

This differential lock control valve is a vital component of the factory Syncro four-wheel-drive system. It controls the vacuum supply used to engage and disengage the differential locks, allowing the driver to select additional traction when driving in challenging off-road, muddy, snowy or low-grip conditions.

When the differential lock control is operated, this valve directs vacuum to the actuator mechanism fitted to the differential. The actuator then engages the locking mechanism, forcing both wheels on the axle to rotate together for maximum traction. Once disengaged, the valve releases the vacuum and allows the differential to return to normal operation.

Over time, original valves can become worn, blocked or develop internal leaks, resulting in differential locks that fail to engage, disengage slowly or operate inconsistently. Replacing a faulty valve helps restore reliable operation of the Syncro differential lock system and ensures maximum performance from the vehicle`s four-wheel-drive drivetrain.

This valve is used in conjunction with the dashboard-mounted differential lock controls, vacuum hoses, retaining plate and mounting holder. It is an essential component for maintaining or restoring the factory Syncro locking differential system.

Quantity: Sold individually

Fitment Notes:

• Vacuum-operated differential lock control valve.
• Suitable for factory differential lock equipped Syncro models.
• Works with the original Syncro vacuum control system.
• May be used for front or rear differential lock circuits depending on vehicle specification.

Vehicle Fitment

Volkswagen Transporter T3 Syncro

• 1984–1992
• 1.6D, 1.6TD, 1.9 Petrol, 2.1 Petrol
• Engine codes including CS, JX, KY, DF, DG, DJ, MV and other Syncro variants

OEM Part Number

• VW: 857711981