Subject: Shift linkages revisited
Author: Tom Bowes
Date: Jul 2, 2001, 10:37 AM
Post ID: 1707339715
Got around to installing the engine, trans, and floor boards on the Ambo
last week and ran into the perennial problem of the sloppy shift
linkage. With a bit of help from Gary Cheek I came with a solution which
had not been suggested before (to the best of my knowledge)on the list.
As most of you know all too well, there are problems with exposed clevis
type joints that are open and are only moved through a small degree of
rotation during the course of their operation. This creates uneven wear
on the linkage surfaces and thus excessive play. The solution that we
came up with is so simple and cheap as to almost be beyond belief.
First of all, I drilled out the offending clevis and pivot arm to 9/32".
Then I took a 5/16 chucking reamer, put it in a tap wrench, and ran it
through both the clevis and the arm, essentially line boring them so
that their holes ran precisely along the same axis. I went to the local
hobby shop and purchased two pieces of thin wall brass telescoping
tubing in 9/32 and 5/16 outer diameters. I also bought a new 1/4 x 3/4"
clevis pin at the local hardware (had to cut it to length, actually).
The 9/32 tubing was slid inside the 5/16 and both were simultaneously
cut with an abrasive cutter (could also use a hacksaw) to a length that
was wide enough to go through the entire clevis/lever assembly. The two
cut pieces of tubing were then deburred, greased, and inserted through
the clevis and actuating lever. The 1/4" clevis pin was inserted and
cotter pinned into place. Voila', a slop-free smoothly operating joint
WITH replaceable parts. Total cost was about three bucks, and I have
enough tubing left over to do about 12 more pivots.
If I had to do this again, I would TRY it differently. If the hole in
the lever was not too worn I would ream it and the clevis out to 9/32. I
would then ream out the clevis end to 5/16. I would cut a piece of the
9/32 brass tubing long enough to go all the way through the clevis and
arm. I would then cut two shorter pieces of the 5/16 tubing to fit in
the ears of the clevis only (one each side). In theory this would give a
full floating bearing to the joint which should reduce wear and drag.
The down side of this arrangement would be getting the alignment right
and getting the short pieces of 5/16 tubing to stay in place. Who knows,
maybe it's worth a try.
Tom
'70 Ambassador
'82 V50-III
Shelby Township, Michigan