Hi All,
Just a comment, ---the aim of the VCU replacement with a selectable 4WD system is simply to eliminate the early Freelander problem of drive train failure caused by a siezed VCU, and still give a modicum of off road performance.
The facility of fancy torque proportioning under a variety road conditions is simply a nonsense if as a result of failing VCU, the drive train spends its on road time f****ing itself.(and in fact could be downright dangerous - catastrophic vcu induced crown wheel/pinion failure at highway speeds for instance!!!)
The VCU replacement is cheap and simple to manufacture and install, allows the car to be an unconstrained 2WD most of the time (99.9% of Freelanders?)
gives simple 4WD when the driver wants it, may give improved mpg etcetc...
Lets face it, none of this would have been necessary if Land Rover had done a proper job on the VCU design and implementation in the first place.
Mad Hat Man's most recent posting pretty well sums it up!!
Having got that off my chest
Pleased (but not surprised). at the response so far to the VCU replacement concept.
The plan is to fit the two splines and sleeve into a cylindrical housing with the yoke and diaphragm actuator mounted externally, -- the yoke accessing the sleeve through a flanged opening on the side of the housing. The half shafts carrying each spline will be supportd by two bearings, in addition there will be spigot bearing or bush between these shafts for spline/sleeve alignment purposes.
Actuating vacuum will come from the manifold (on my petrol 1.8).
The original Ford Raider setup uses two separate solenoid valves to direct and control vacuum to, and venting of the diaphragm. My concern initially was that if both solenoids are deactivated (electrical fault? always a possibility on a Freebie) the system could vent the manifold vacuum to atmosphere with some problems for servo assist on the brakes! A bench test seems to show that Ford worked it out correctly!!
All I need to do now is to get my mech eng mate off his bum and do the bit of machining/assembly work.
Cheers
Ian Hughes
Tassie