Re: Crunchy Second Gears

[Simon Favre <simon@domain.elided>]

Groan, here we go again... ;=)

Let's step back in time a bit and examine the history of the Alfa
transmission, at least in the post-war era, and after they made the
sensible decision to go from a tunnel-case to a split-case tranny.
That would place us in the era of the Giulietta. Alfa had recently
licensed a synchro design from Porsche. It isn't the design that's
at fault, it's the implementation, and the total system that's a bit
flawed. At the time of the Giulietta, the vast majority of the Alfa
gearboxes were 4-speed, as fitted to the Giulietta Saloon. As John
H. is fond of point out, the bulk of Alfa's mass-produced cars were
sedans. In the 4-speed there is little or no problem with crunching.
That's the basic design they started with.

When the Veloce models came out with a 5-speed, Alfa did little to
the overall design of the tranny, other than sticking an overdrive
5th gear out in the tailpiece next to reverse. Unfortunately, what
this did was add a large rotating mass to the tranny countershaft.
In order for 5th to be an overdrive, the 5th speed gearwheel on the
mainshaft has to be smaller than the mating gear on the countershaft
(not true in the general case, but in this case, it is). The large
gear added to the countershaft aggravated the situation enough to
cause perennial gear crunching in later models. As each gear is
brought into synchronization (that's the synchro's job), all that
extra mass has to be spun up or down to the right speed or you get a
CRUNCH.

OK, so after all this, what's the ^%#$&^*&^ problem with 2nd? The 
underlying cause of the crunch is the fact that Alfa's have had a
large gap in the gear ratios between 2nd and 3rd for a very long time.
Think about how the Italians intended the car to be driven. You're
supposed to rev the p*ss out of it in 2nd before shifting to 3rd so 
you can accelerate smartly with a small engine. Once you shift to 3rd,
you have the momentum and power to carry the car all the way up to
freeway (or Autostrada) speeds. 3rd is the most flexible gear in most
Alfas. When you do have to downshift to 2nd for a tight turn, then the
ratio gap and the extra rotating mass of the 5th gear additions sneak
up on you and make you crunch the gears, unless you are well practiced
in the art of double-clutching.

So, how come Alfa NEVER fixed this problem? There could be a number of
reasons. As Tom Sahines has pointed out, the most elegant cure is to
lighten the gears. This has to be done with care. Tom showed me a gear
that had been excessively lightened. It shattered inside the gearbox,
with disastrous results. Alfa probably didn't want the liability of
having hamfisted drivers shatter lightened gears. So why not just make
the synchros beefier? Have you ever tried forcing, say a Ford truck,
into 2nd when it didn't want to go? You could sprain your wrist doing
that. It was perhaps a classic case of Italian arrogance (Alfa's so-
called Marketing Dept. strikes again) that made them think any driver
worthy of owning an Alfa would have to learn to drive with the right
amount of finesse. In order to support stronger, more durable synchros,
they would have to beef up the whole shifting mechanism. That would
detract from the true sense of style they applied to their cars quite 
nicely.

In racing, of course, all such considerations are irrelevant. Alfa did
lighten the gears in race cars. They even went so far as to gun-drill
the mainshafts, which I consider excessive. They also made close-ratio
gear sets. Just try to get get a true GTA close ratio, magnesium case
gearbox for less than a small fortune.

All road-going cars are a compromise. Alfa most likely never fixed this
long-standing problem in their road-going cars due to some compromise.
Alfa's engineering was clearly equal to the task, but the problem was
never addressed due to other considerations we can only speculate about.
Perhaps they didn't want to have to license another synchro design, or
get sued over possibly infringing on someone else's if they did their
own. Perhaps they just wanted to make more money in the service dept.
Perhaps they saw it as part of the "character" of the cars. They surely
could have fixed the problem when they started over on the transaxle
cars, BUT NO!! ;=)

Simon

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End of alfa-digest V7 #1250
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