Hi Rob,
Sorry to hear you have a problem with your Ferret transmission.
You probably already know, but incase you are unaware of the operating
techniques of a 'Wilson pre-selector box', here are a few pointers.
The Wilson box is self-adjusting for wear. Very few operators
understand the correct use of a vehicle fitted with this kind of
transmission. From cold, and before attempting to start the engine.
The gearbox should be adjusted for wear. This is done by engaging each
of the five gears in turn, and depressing the foot change-gear pedal
five times vigourously through each one. This will set the adjusters up
evenly to the correct position to compensate for band wear.
Unfortunately if this is not regularly accomplished the wear reaches a
level where it can no longer auto adjust.
Another point of interest regarding the 'Ferret', often not understood.
Is the correct driving technique. It is common to find that Ferret's in
private hands who have not had proper driving tuition, regularly
overheat the gearbox and in turn through heat transmission the fluid-
flywheel, causing the subsequent breakdown of the oil seal in the
flywheel. This further compounds gearbox and transmission wear due to
lack of proper drive. The gear changing and engine idle speeds of the
Ferret are very different to the average car. A general rule of thumb
guide is that ......when the rev's feel about right for either idle or
gear-change take them about another 25% further. The minimum idle
engine speed of a Ferret is 800 to 900 rpm. And at least 4000 to 4200
should be reached before attempting to change gear. The Ferret has a
forced-air, with multi-blade fan cooling system. As well as creating a
considerable drag load, it requires a critical minimum rpm to keep
engine and transmission at proper temperature levels.
The gearbox/transmission is identical for all marks of Ferret.
P.S A dragging brake, as well as trying to use the change-gear pedal
like a clutch pedal, are also major contributors to excessive gearbox
band wear.
regards
Colin Brookes
Invicta Military Vehicle Preservation Society (IMPS)
colin@h-bplan.demon.co.uk
-- Colin Brookes