A previous thread last week stimulated by Graham revealed a very damaged set of gears. Unlike my later 1932 onwards 4 speed gearbox which has a cam/sprung plunger system there does not appear to be a positive indexing system to assure the gear change arm is in the proper position for the AT/BT/CT series. This can cause the gears in the layshaft to be only half meshed casing some horrible mashing of gears.
Would anybody care to describe how to set up the gear change selector mechanism properly?
Vic
ref Heathcote
'Gear-box (sliding pinion type)
Adjustment of control. To check the adjustment, put gear lever into neutral notch, turn back wheel, and bring lever slowly from neutral towards low gear position. Note the exact point at which gears are first heard to touch. Then repeat the operation, moving lever towards middle gear and again note the point at which gears first touch.Finally, note the point which is exactly equidistant from the other two. If this central point does not coincide exactly with the neutral notch, detach the upper yoke on the operating rod from the change speed lever, loosen the lock-nut and turn the yoke as necessary. If the central point is on the low gear side of the neutral, screw yoke father down the rod. If the central point is on the middle gear side, screw the yoke farther up. Finish by tightening lock-nut on yoke.'
Hope this helps kind regards WM.
nice one Dave and thanks
Vic
Hi Folks
I have just posted a video of the steps described by Dave on the club website. I did this following the re-build of my 1930 gearbox and all seems correct.
http://www.marston-sunbeam.org/technicalNotes/Model9GearboxAdjustment.html (http://www.marston-sunbeam.org/technicalNotes/Model9GearboxAdjustment.html)
Graham