triumphs
[Top] [All Lists]

Re: TR4's

To: triumphs@autox.team.net
Subject: Re: TR4's
From: Chip Old <fold@mail.bcpl.lib.md.us>
Date: Tue, 21 May 1996 01:15:01 -0400 (EDT)
On Sat, 18 May 1996 FNSortwell@aol.com wrote:

> First thing noticed was that I could go into reverse without pulling up. 
> Is this an internal thing, or some external ramping?  I didn't do the
> tranny rebuild.  Have to be very careful to pull straight back from
> third gear.  Any easy fix? 

The ball at the bottom end of the gearshift lever engages cups on the ends
of the three shift rods in the gearbox cover.  The bottom of the cup on
the left-hand rod (for reverse) is higher than the other two, forcing you
to lift the lever in order to move the ball into the reverse cup.  This is
a simple form of reverse lockout to prevent accidentally engaging reverse
gear.
 
If you no longer have to lift the lever to engage reverse, then any of the
following could be the cause:
 
o The rebuild shop ground out the bottom of the cup to match the others in
  a misguided attempt to "fix" what they believed to be a manufacturing
  error.
o The rebuild shop ground off the bottom of the lever for the same reason
  as above.
o The rebuild shop assembled the shift lever incorrectly, in such a way
  that the lever is not set as deep into the gearbox cover as it is
  supposed to be.
 
Any of the above would cause the bottom of the lever to skip right over
the lockout.  The only way to diagnose this is to take out the shift lever
and take a look.
 
This type of reverse lockout was used from TR3 through (I think) early
TR6.  In late TR6's the bottom of the reverse cup was formed into a ramp,
so you could get into reverse by forcing the lever hard to the right
(without lifting).  Unfortunately this setup combined with typical lack of
lubrication tends to wear both the ramp and the bottom of the lever pretty
quickly, so in really bad cases almost no force is required to move the
lever into reverse.  It's a long shot, perhaps, but could the rebuild shop
have substituted a badly worn late TR6 tranny (or at least the shift rod &
lever assembly from one)? 

-----------------------------------------------------------------------
Chip Old                      1948 M.G. TC  TC6710  NEMGTR #2271
Cub Hill, Maryland            1962 Triumph TR4  CT3154LO (daily driver)
fold@mail.bcpl.lib.md.us
 
If cars had evolved as fast as computers have, by now they'd cost a
quarter, run for a year on a half-gallon of gas, and explode once a day. 


<Prev in Thread] Current Thread [Next in Thread>