There are essentially two shafts in the tranny. Both
have several gears on them. One shaft (the input shaft)
is attached to the engine. The other one (the output
shaft) goes to the wheels. (Well, actually, to
the differential. But close enough.) The gears on the input shaft are welded or otherwise
permanantly attached to the input shaft at all times.
These "input gears" are also always meshed with the
"output gears" on the output shaft. But here's the
tricky part. The output gears on the output shaft?
They're NOT always attached to the output shaft! Most
of the time, they spin freely without causing any kind
of turning motion on the output shaft. It's only when you
move the shift lever into a certain position that one
of the output gears gets attached to the output shaft. By moving the shift lever and causing one of the
output shaft gears to connect up with the output shaft,
you're making a connection all the way from the input
shaft to the output shaft, via the two gears that you
have "chosen." Well, you really only chose one - the one
on the output shaft. But since that output gear is
always meshed with its corresponding input gear, you've essentially chosen two gears. The two gears you choose generally have different numbers
of teeth. One may have 15 teeth, the other may have 12.
This determines the gear ratio between the gears. A
tooth ratio of 15:12 is the same as a ratio of 1.25:1 (because 15/12 = 1.25). So this gear would have a gear
ratio of 1.25:1. This is close to third gear (1.30:1) in
your Z. First gear, by contrast, is about 3.21:1. This
would be about like having one gear with 32 teeth and
the other with 10. And finally, fourth gear on our
Z's is actually a 1:1 gear ratio, so the fourth gear
gears have the same number of teeth.
I won't go into spiral-cut gears, or how they manage
to do reverse, or hwo synchromesh works. Read these
web pages below if you're interested, since
HowStuffWorks.com explains this a lot better than I can...
Gears in general: [ http://www.howstuffworks.com/gear.htm ] Manual transmissions: [ http://www.howstuffworks.com/transmission.htm ] And, incidentally, Marshall just put up a really sweet
page about rotary engines... [ http://www.howstuffworks.com/rotary-engine.htm ]
-Ben
Ben Cantrick, mackys@dimensional.com
Black 1994 TT. |
