Hi folks.
I'm startin' to hear some noises, guys. Within the last couple of
weeks there have been two or three occasions where suddenly and
inexplicably it was difficult to get into first gear at a standstill,
and then subsequent shifts were a little tricky, almost as if the
clutch wasn't disengaging. And then, quickly as it came, the
condition would vanish and everything would work smooth as silk
again. I've had plenty of clutch linkage failures (mostly hydraulic)
and I've learned that those are never intermittent, so this seemed a
little strange. But I wasn't all that worried about it.
But then this morning on a trip across town I heard some noises
coming from the gearbox, and I could actually FEEL them slightly in
the gearstick. The noises were very occasional and random
(definitely NOT rhythmic or 'rotating') and were generally of the
"crunchy-clicky" variety as opposed to the heavy "clunky-knocky" type
noises. I only heard these noises while in 1st or 2nd gear, and at
times this morning it did feel a little stubborn getting into 1st
while at a standstill.
One clue to diagnosing the problem that may be developing here is
that back in 1989 when I rebuilt this gearbox, I discovered that the
bore in the 1st gear end of the layshaft (where the layshaft bearing
goes) had worn out to a diameter that would allow the new bearing
cage to simply fall right in, rather than being a press fit like it
should be. At the time I seem to remember a new layshaft was
incredibly expensive, so on the advice of my machinist I repaired the
layshaft with a Loc-Tite product called "Bearing Lock." It's used
for temporary repairs in heavy equipment, etc. Essentially, I
'glued' the bearing into place. This repair has served me well for
about 40000 miles, but I suspect that this may be where the problem
is developing.
I actually had to rebuild the box twice back then. The first time I
didn't know to be concerned when that bearing just fell into that
hole upon assembly. I put it together like that and sure enough, a
couple of thousand miles later the bearing was toast and I had to
pull the box again. This is when I used the 'Bearing Lock."
Remembering back to when that bearing was going out, I recall that it
was becoming difficult to get into 1st and 2nd gears even though the
clutch was operating normally. So that's partly what is leading me
in that direction. Trouble is, knowing now how the gearbox works, I
don't quite understand why a bad layshaft bearing would reveal itself
by making shifting progressively more difficult. When shifting,
you're not doing anything to the layshaft
only the mainshaft. So
why would a failing layshaft bearing translate into difficult
gearchanges?
At any rate, I may have a rebuild coming. Anyone have any other
insight on how to proceed? Naturally I intend to drain the oil and
check the magnetic drain plug for shrapnel, and that may lead to
removing the top cover and taking a peek inside. Any other words of
wisdom would be greatly appreciated!
--
Pete Chadwell
1973 TR6
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