Wilson Self Changing 4 speed Gearbox parts

Who should I contact to advise that I have these parts for sale. I have Planetary gears, sun gears and three stage cylinders.

Wack up pictures & prices and see what happens. The components are probably/possibly the same as used in the 5 speed splitter which several members have in their trucks.
As the 4 speed were used in buses there may be a bus forum equivalent of this site??

bus chat forum is on www.busaustralia.com

Can someone give me a run down on this Wilson self changeing box...never seen one.
I gather its a pre-select setup but hows it work ?

Basil

gibbo,bus preservation society at Whiteman park Perth may be a possibility to contact they run an old Guy Arab 111 with Wilson pre select(if that is what you have).i drove my old 1953 ex MTT Guy to Queensland back in 2000 no worries and sold it to a guy in QUOCS Queensland Omnibus and coach society so may also be another point of contact,i think that may be quite a few old pommy buses ran that box bont know about trucks tho

gm-diesel,the pre-select box had "clutch pedal" described as a change speed pedal so you merey placed small gate selector in 1 put foot on "clutch pedal" and released and simply applied some accelerator and moved off select 2 and when ready dip "clutch' upshifts were relatively quick and smooth up to 4th ,reverse for downchanging, but making sure on both upshift and downshift that you didnt actually move the selector when dipping the "clutch" it didnt seem to like it and you would end up with no drive sometimes, you could sit in gear no prob at idle,but with the Leyland semi auto you couldnt,no lockout meant you could start the engine and if you had not put it in neutral when last driven/stopped when it had built up air it would simply move off!(i did this lucky i was standing behind drivers seat at time and managed to hop in and depress "clutch" to disconnect

Baz - The Wilson preselect gearbox is a clever bit of work, that involves the bringing together, of three main components ..

1. A "fluid flywheel" or torque converter ..
2. A number of epicyclic or "planetary" gearsets ..
3. A gear-changing mechanism that involves a hand-operated gear selector, coupled with a foot-operated "actuator".

The entire Wilson pre-select transmission setup is very compact, due to the epicyclic or planetary gearsets. It is also very efficient, with low power losses in transmission.

The fluid flywheel or torque converter gives the ability .. as with a full automatic transmission .. to allows the engine to idle, with a gear engaged, and not move off, until the accelerator is pressed, and the revs brought up.

In the Wilson PSG, there is, in order, from front to rear .. the fluid flywheel or torque converter .. a multi-plate clutch .. 3 or 4 planetary gearsets (depending on whether the gearbox is 4 or 5 speed) engaged individually, as required, by brake bands located on the outer smooth drum surface of the planetary or epicyclic ring gears .. and hydraulic or air mechanisms that engage the selected gear, as required.

The clutch pedal, as fitted to a manual transmission .. is replaced by an actuator pedal in the Wilson PSG. It looks like a clutch pedal, but its operation is totally different to a normal clutch pedal.
The actuator pedal disengages all transmission operation by being depressed. This is the equivalent of throwing a manual transmission into neutral and releasing the clutch pedal.

Releasing the actuator pedal actuates the hydraulic or air cylinder that clamps the band attached to the gearset, that has been previously been selected by the hand lever (thus "pre-select").

When top gear is selected, hydraulic or air pressure actuates the multi-plate clutch, that is mounted at the front of the gearsets .. which effectively locks all the gearsets together, thus giving direct drive.

In operation, the Wilson PSG is operated by pre-selecting the required gear on the hand selector, and depressing and releasing the actuator pedal.
This engages the gear selected, by the actuating piston clamping the band on the appropriate gearset .. but the vehicle does not move until the accelerator pedal is depressed.

A driver alway has to think ahead with a preselect transmission, and have the preselect lever in the notch for the next gear required, prior to the actual gear selection.

In operation, the Wilson PSG is a little slow by todays standards .. but they are a very effective transmission where a lot of gearchanging is required .. and they are very smooth in operation .. provided the driver allows for the 2-3 seconds lag in the actuating mechanisms, for actual gear takeup.

Cheers - Ron.