[VAC] Re:

[harriswest <harriswest@xxxxxxxxxxxxx>]

Huh??? 

Doc, I just rebuilt my Toyota W59 five-speed, about as modern as you can
get, and the gears definitely slide along the mainshaft to
engage/disengage with the cluster gear.  There isn't a dog clutch in the
whole gearbox. If all gears were meshed all the time, the thing would be
locked solid.  

Disconnect your driveshaft, take off the top cover of your manual
gearbox, and with a big screwdriver force (for example) your
first/reverse gear and your second/third gear into mesh simultaneously -
doesn't matter which way (the top cover mechanism contains lockouts to
prevent this from happening normally).  Mash the clutch pedal and try to
turn the works with the clutch disengaged - it ain't gonna happen.  Dont
try running the engine with the gearbox locked up like this of course.

> Since the oil temperature may go up to 350 F you say, I say it doesn't
> make much difference whether it starts at 120 or at 100, the rise is a
> great deal more than the difference in ambient. Sure the oil temperature
> will be higher and the cooling less effective with the ambient hot, but
> not all that much.

Well, no, not as such, as the trans itself will reach equilibrium at
about 350F regardless of ambient.  It's got that nice, cool 220F water
jacket to unload its heat into.  At 120F ambient, though, the
equilibrium temperature of the cooling system as a whole is very likely
to be above its overheating point. 

You are absolutely, 100 percent right about "can't get too cool."  If
you tow, get the biggest rad and trans cooler there is.  Overheating is
an engine-killer (particularly with the GM small-block V8's).
-- 
Mike Harris
Austin, TX