> I'm want to perform a visual check of a tr3-4-6 transmission. I'm
> going to remove the top of the case. What should I be sure to look
> for in a trans of unknown condition.
Actually, there's quite a lot you can tell just by removing the top
cover. First a couple words of advice. The top can only go back on if
the box and the shifter are in the same gear. I recommend that you put
it in neutral before you first open it. Also, have a new gasket ready to
properly reseal it when you're done.
First, there are narrow, pointy little teeth on a "dog gear" associated
with each speed gear, at least the ones that have syncromesh. You can
check these teeth for wear. Wearing of these teeth can cause the box to
jump out of gear under heavy acceleration or engine braking. You can
also check the drive gears themselves for chipped teeth, and for signs
that the hardening is wearing through. Spin the input shaft a few times
to rotate all the teeth into view.
If the box is out of the car, you can wiggle the input shaft up and down
or side to side and see whether this results in any visible movement
inside the box. This would indicate a shot bearing between the main and
input shafts, but the bearing could be shot without you being able to
wiggle it, too.
You can also reach in and pull the syncros up against their respective
dog gears. Measure the space between them. If the syncro goes flush
against the dog gear, then it's totally shot. Check all 3 (all 4 if you
have syncro on 1st gear). If the best one has, say, 50% more clearance
than the worst one, then you're going to occasionally get gear gnashing
on the worst one (pity those poor dog gears). Sorry, I can't provide
numbers for new and wear limit clearances.
Bill Kelly
'62 Herald, GA41328LCV, in restoration
I want my car back!
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