[Shotimes] MTX shifting difficulty hypothesis

[Justin Schick]

I've been through enough clutches (and now a tranny) to start catching
on to a trend I wanted to share. Most recently, I've posted about notchy
shifting and hard 1st gear engagement with a new OEM clutch in front of
my fresh MTX with quaife. Around the time I posted this, there was also
a thread about a guy inching forward in first with the clutch depressed
and revving the engine up. Soon afterward I noticed my car do the same
type of thing, only in reverse at idle.

My thought was the internals inside the transmission were not spinning
down in idle, or being spun by too-close tolerances around the fat new
friction disc. I had previously checked for cable slop but installed
slotted a washer to shim the cable on the transmission end, thinking the
adjuster mechanism may need help. No luck. I ordered the delrin ball &
socket upgrade from SHONut (which showed up today) and some Redline MTL
(used Mobil 1 ATF during the install) from Summit (showed up last week).
I changed the fluid yesterday, which helped the slight notchiness
between gears while moving, but not 1st gear engagement at a stop. I
developed a workaround for that last week. Assuming the internals
weren't spinning down in neutral, I decided to spin the engine up before
trying 1st. After teaching myself this new driving style, viola it
plunks right in every time. I don't know why it didn't strike me before,
but it's just like rev matching for a downshift. Kinda.

Anyway, I'm wondering if anyone with a new clutch and shifting problems
could corroborate my results. I'm also wondering what the thickness of
aftermarket friction discs is compared to OEM, and if the problem is
truly a too-thick disc or something else (flywheel thickness, PP
geometry, transmission alignment?). What do you think?

Justin 
'92 SHO in KC MO, 190k and counting
SHOTimes list info: http://www.shotimes.com/SHO1.html