Mark, Bob, etc.:
Dave gave some good reasons for the problem now to add my 2 cents.
Not only are the TC through early MGB transmissions not synchromesh on
first gear they aren't constant mesh.
4th gear isn't really a gearing, but the locking together of the input
and output shafts of the transmission. The synchronizer mechanism is to
ensure that both shafts are rotating at the same speed for locking.
Locking occurs when the 3rd-4th hub slides over the "teeth" on the
output shaft.
2nd and 3rd gears are actually reduction gears but they are in constant
mesh. The gears aren't slid into allignment but locked to the output
shaft. The power comes in the input shaft, it drives the counter gear,
and it in turn rotates the 2nd and 3rd gears which are free to rotate on
the output shaft. When either is engaged, the gear is locked to the
ouput shaft to transfer their rotation to the prop shaft.
As Dave points out, the locking teeth on the synchromest are much
smaller and stay pointed when compared to the first gear. Besides that,
there are more and they are closer together. The first gear teeth on
the counter gear are about 10-12, while the locking teeth used on the
second gear synchonizer are probably more like 30. First gear could
have to rotate 15 or more degress to line up while 2nd or 3rd may only
need 6 degrees of rotation to line up. Thus the 2nd and 3rd gears have
to rotate much less to line up with the locking rings and teeth.
There could also be the a problem in that you have some slight driven
disk drag in the clutch. If there is rust on the pressure plates, or
rust and dirty and thick grease on the driven disk where it slides on
the transmissions input shaft the clutch may not completely release.
When the drive train is cold, the oil is thicker and it offers more
resistance. Thus when the clutch is depressed, the the oil stops the
tranny gears. Once the oil is thinner it may not be able to keep the
input shaft from rotating which makes engagement more difficult.
You'll just have to get used to it or make adaptations to your gear
change techniques.
Blake
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