Viscous Coupling Unit (VCU)

Viscous Coupling Unit (VCU)

Service repair no - 41.20.66/01

Remove
1. Remove front output shaft drive flange.







2. Remove 6 bolts securing VCU housing to transfer box.
3. With care, break front face RTV seal and remove VCU assembly.
Do not carry out further dismantling if component is removed for access only.

4. Press out viscous coupling from housing.

CAUTION: Protect output shaft thread and do not use excessive force when pressing out viscous coupling.

Refit
1. Clean mating surfaces of viscous coupling housing and transfer box.

CAUTION: Do not use a metal scraper as this may damage sealing surfaces.

2. Clean bearing and VCU mating faces.
3. Press VCU into bearing.
4. Apply a continuous 2mm bead of sealant to VCU housing mating face. Path to be around inside of bolt holes.
5. Fit VCU assembly to transfer box ensuring correct alignment of bolt holes before disturbing RTV bead.
6. Fit bolts and progressively tighten to 35 Nm. (26 ft. lbs.)
7. Fit front output shaft drive flange.