[DeTomaso] Drifting Out of Third Gear - The Rest . . . . . . . of the Story

Mike Thomas mbefthomas at comcast.net
Sun Jan 29 13:51:22 EST 2017


So, I just put out a post regarding evidence of no wear on my non-steel
syncros that Byron Sanborn, Vintage Racing Motors, sourced from Dennis for
my ZF rebuild 6 years ago (checked my records).  In there I mentioned
something about the box drifting out of third gear.  So, here's the rest . .
. . . of the story.

I've been putting up with the box drifting out of third gear, and once or
twice from first, for the past 3-4 years.  It would usually be more frequent
the box was cold, and usually when I would lift on the throttle, but
unfortunately once or twice when under hard acceleration (ouch).  I finally
got fed up enough, after checking all my linkages and replacing a broken
clutch lever arm which in its' weakened state prior to breaking I had
attributed the third gear problem to, and pulled the box for Byron to take a
look.  Conversations on the phone prior led him to think that I may have
compromised the engagement ring for some reason.  Upon cracking the case and
pulling the gear set out, he could see no evidence of wear, all the shifting
forks were properly adjusted and everything was working as it should on his
bench test.  It wasn't until he had it buttoned back up and was working the
shifter in hopes of finding a solution that he noticed that the aftermarket
boot on the end of the shift rod at the shifter box was too thick and, when
pushed back as it would be for third gear, was bunching up and not letting
the arm move back enough to solidly engage third gear.  So, he ordered what
he thought would be the thinner OEM boots that they originally came with and
which he also admitted were far too fragile, but what he received was the
same thicker version that I had on there to start with.  I had replaced that
boot myself after the rebuild, and even then recall being told the original
versions were no longer available.

So, he removed the collar from the shifter arm and machined the backside
enough to allow the arm to fully engage.  Now the pilot is out, I can put it
all back together and take if for a drive to see if indeed this does solve
the problem.  All crossable appendages crossed ;-).

Mike Thomas
Pres., Panteras Northwest
Yellow '74 #6328





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