I am no expert, but I have rebuilt over a dozen Moss boxes. Failures seem to
be caused from abuse (esp first gear) and from trash in the oil. There is a
pretty small oil feed to the countershaft bearings that seems to be plugged
with trash more often than not.
Seldom have I seen actual "wear" on the synchro faces. A more likely problem
is that the detent springs in the hubs have fatigued, which reduces the
pressure of the synchros. In theory- and in practice most of the time- there
is always a film of oil between the synchro surfaces. Wear may occur- again-
with trash in the oil, but with clean oil- no..
When you rebuild the box- check the amount of pressure that it takes to
dissengage the sleeve form the neutral position on the hub.
3rd /4th should be 52-58 lbs
1st/2nd should be 62-68 lbs
Use new springs or shim up the old ones with small washers- new is better
tho.
If your box shifts very easy- it's a good bet that the springs are fatigued.
Properly set up, some effort is required to move the gears- that effort is
the detent springs working.
These are not "true" synchro boxes- they are "kinda" synchro boxes. With
older, easy shifting boxes, give 'em a little time- "nudge" the lever aginst
the next gear for the synchro clutches to bring the next gear to speed.
Whatever oil you use- change it often to flush out the gear chips... You will
be rewarded....
Fred Sisson
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