Subject: [TR] Trans shifting issues - links to gear pics - how bad is too bad?

From: aribert neumann <[email-masked]>
Date: Thu, 19 Jul 2012 22:19:18 -0400

Greeting all

The trans in my Spit bodied GT6 has some issues.  I have to pause (about 1
sec) on a first to second gear upshift.  Downshifting from third to second
and second to first are also difficult.  THe 2nd to 1st downshift needed to
take place when the car was slowed down to less than 10 mph.  Gear clash
ensued if I shifted too fast.   Since I have the trans out to replace a
slipping clutch, I figured to have another look at it (I had the trans
apart 20,000 miles ago - in Spring of '04).

In the past 8 years,  I aquired a NOS 1st gear and 1-2 shift hub
asm.  Second gear was the elusive NLA part but looking at Rimmers web
catalog today, they now have them in stock.    Also when I refreshed the
trans in '04, I did not replace the synchros - I measured the gap between
the original synchros and the mating gears - all were well above 0.030 gap
so I reused them.   Since there had been the bad batch of synchros sometime
in the '90s, I was concerned that all of the marginal parts were not used
up.  Now I am going to use the synchros that I bought in '04.

I was thinking that the engagement teeth on the synchros and the matching
engagement teeth on the shift hub and the 1st and 2nd gears were the cause
of the shifting problem.  I was expecting to see more wear when comparing
old parts to new.  Synchro on first gear:
http://i290.photobucket.com/albums/ll272/aribert/Triumph/1stgearsynchro.jpg
Synchro on 2nd gear:
http://i290.photobucket.com/albums/ll272/aribert/Triumph/2ndgearsynchro.jpg
First gear, worn gear is on the right:
http://i290.photobucket.com/albums/ll272/aribert/Triumph/firstgearnewold.jpg
http://i290.photobucket.com/albums/ll272/aribert/Triumph/firstgear2.jpg
Shift hub, both sides appear to have very similar wear, worn hub is on the
left:
http://i290.photobucket.com/albums/ll272/aribert/Triumph/1-2shifthub.jpg
http://i290.photobucket.com/albums/ll272/aribert/Triumph/1-2shifthub-1.jpg  And
finally 2nd gear:
http://i290.photobucket.com/albums/ll272/aribert/Triumph/secondgear.jpg
http://i290.photobucket.com/albums/ll272/aribert/Triumph/secondgear2.jpg

So for those of you who have trans rebuild experience - does the wear on
the matching engagement teeth look like it would be enough to cause
shifting difficulties?

BTW, I did all the bushing / spacer feeler checks last time and will be
doing them once again.

And a final note - yes I could learn to double clutch but I'm a lazy
shifter (even though all 5 of the vehicles in our family fleet are manuals).

** [email-masked] **

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From: "Randall" <[email-masked]>
Date: Thu, 19 Jul 2012 21:17:29 -0700

> the matching engagement teeth look like it would be enough to cause

My experience with gearbox rebuilds is (very) limited to the TR3/TR6 units;
but those parts look OK to me.  Given that you are having problems, I might
roughen up the cone surface just a bit (break the glaze).

> BTW, I did all the bushing / spacer feeler checks last time 

You didn't mention checking the detent force in the shift hub.  Very
important (it is what applies force to the synchro rings during the shift)
and almost always too low.

-- Randall