[Shotimes] MTX shifting difficulty hypothesis

[Leigh Smith]

Justin   ;

My 94 does almost exactly the same thing. Gears are still spinning at a 
stop and almost impossible to engage first.  But mine is inconsistent as 
h***l.
 A local tranny expert or two labled mine "disk drag".


I found three spin-down tests in Helms that go like this;

1) Release clutch in neutral, depress, wait 20 seconds, should go in 
reverse O.K.
2) Ditto the above, but put shifter "halfway" into reverse.. Slow...ly 
release clutch and note how many inches off floor gears begin to spin. 
There should be some 2 inches "safety release margin"
3) After put in reverse, remove to neutral, wait few seconds, try to put 
back in reverse. Should be OK

My old 89 passed all 3 of these for 10 years and 200k miles on the same 
Ford replaced second design, small dia clutch.
My newer 94 has a centerforce that worked fine before the tranny 
replacement. After adding the known good shifting tranny, it does does 
this.

But it shifts like butter while moving, or if I put into first at 5 mph. 
First gear balking is inconsistent, sometimes good, others bad. 
Inconsistently flunks test 1 or 3 above. Some temperature correlation. 
Very light pedal. No noise.

Current hypothesis(es): Good throwout bearing & cable, (wrong symptoms) 
Warped / bent clutch disk, tight disc fit on input shaft,  or warped 
pressure plate cover from incorrect bolt torquing. Possibly bad 
fingers;  but no noise???
 
Anyone else got any ideas?
To help me confirm what to buy before I tear it apart?

Leigh

Justin Schick wrote:

>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
>_______________________________________________
>Shotimes mailing list
>Shotimes@autox.team.net
>http://www.team.net/mailman/listinfo/shotimes