1991 100q difficulty shifting

[laraa at sympatico.ca]

Well, Grant, I have some other clues : in neutral shifting in first, with
the wheels at zero mph, the first gear synchro must stop the main shaft
completely to engage first gear. One can overcome this by waiting long
enough with the pedal depressed for the mainshaft to stop spinning by
itself, then engage first gear. Hence the difficulty if the clutch (pressure
plate, release bearing or slave cylinder) keeps spinning slightly. Or if the
1st gear synchro is too worn. 

When shifting into second from first, or going up the gears, then the main
shaft speed is faster than necessary (for the upcoming gear), so one has
just to wait for it to slow down and engage the next gear without much
effort from the synchros. Hence the easier shifting he experience.

Think of the case where the clutch cable has snapped (or when you go up the
gears without pressing the clutch pedal) : you can easily pull on the lever
from first, pass neutral and try to engage second and when the speed of both
part of the gear pair are equal, it will drop in second. That why the next
gear changes are easier, IMO.

So wadd-wadd, you have a few more tests to do :

Engine off, shifting in various gears with the clutch pedal to the floor.
Should be same effort for each one. You don't force select the gear, you
just let the lever gently move by 2 or 3 rocking movements. If this is
difficult, maybe simply the shift lever needs adjustments/repair. But I
doubt it.

Engine running, clutch pedal on the floor for 5 to 10 seconds, then try
first gear : if easier than usual (or easy as normal), synchro is
dead/dying. If still hard to select first, clutch is not disengaging fully.
Find the cause.


Louis-Alain


-----Message d'origine-----
De : Grant Lenahan [mailto:glenahan at vfemail.net] 
Envoyé : 16 janvier 2012 17:59
À : laraa at sympatico.ca
Cc : wadd-wadd at usa.net; quattro at audifans.com
Objet : Re: 1991 100q difficulty shifting

If that was true, why would it be OK if he shifts gear to gear relatively
quickly, but not if he waits in neutral?
According to your theory, both shafts would continue spinning more or less
as they were, since the clutch would not disengage (slave cyl theory).

I still want more facts - every gear has this problem?

Grant

On Jan 16, 2012, at 5:43 PM, <laraa at sympatico.ca> wrote:

> My second thought is for a worn pressure plate or release bearing or a
slave
> cylinder out of adjustment. Clutch doesn't disengage fully, main shaft is
> still spinning a bit, 1st gear synchro does its job by attempting to slow
it
> down (hence the resistance). Other gears are easier since the speed
> differential is less. 
> 
> You can test the behavior by leaving the trans in neutral, and try to
shift
> into second or third from there. If resistance (less than in first, but
> still), my bet is on the clutch. Shut the engine, do the same : if no
> resistance in first, (except for the gear meshing together), it would
point
> to the clutch. 
> 
> Anyone can destroy my theory ?
> 
> Louis-ALain
> 
> 
> -----Message d'origine-----
> De : quattro-bounces at audifans.com [mailto:quattro-bounces at audifans.com] De
> la part de Grant Lenahan
> Envoyé : 16 janvier 2012 16:29
> À : wadd-wadd at usa.net
> Cc : quattro at audifans.com
> Objet : Re: 1991 100q difficulty shifting
> 
> My first thought is worn synchros.  When you shift quickly both shafts are
> spinning. When you go to neutral, one spins down.
> 
> Grant
> On Jan 16, 2012, at 4:18 PM, wadd-wadd at usa.net wrote:
> 
>> I have difficulty changing gears on my 100q, cold or warm. The car has
> ~201k
>> miles.
>> 
>> Once the shifter goes into a gear, the rest of the gear changes are silky
>> smooth.
>> 
>> If I allow 30 seconds to pass by in neutral, the same things happens
> again. 
>> 
>> The fluid has been changed with OEM fluid and is not low. 
>> 
>> Is there any type of an adjustment on this gear box? 
>> 
>> Thanks.
>> 
>