Let's have a look at what to check for on the main mechanism:
1. The two forks in the base plate need to be level and unbent.
2. The threaded rod for the adjustment should be perfectly straight. It is actually a press fit into the forked plate so make sure it's rock solid and not loose.
3. The thread in the plastic lever should be unstripped and the lever not snapped in any way. The weakest point in this plastic piece is the slotted hole with the rivet in it at the other end.
4. The sliding snare wire
carrier is two plates
riveted together. Make sure
the bottom plate has right
angled corners and is
parallel to the top plate
for a good
fit on the forked base
plate. This will minimise
rotation of the
wires.
Once you are happy the mechs are in good shape the next thing to look at is alignment when mounting the mechanisms to the shell:
Above: Mount the mech level with the snare bed, the holes in the shell do allow some movement and just fixing the mech's on doesn't guarantee level wires! I use the arrowed edge as a reference when doing this.
For a quick check you can do a partial build minus the hoop to see if you are in the ballpark too:
If the wires are floating a touch high try mounting the mechs lower by loosening the two screws and pushing down whilst tightening. If one corner is raised re-check tightening the screws hasn't lifted the mech out of level!
That deals with the two bottom halves of the mech. Now for the linkages:
Each linkage has two screws, the bottom one adjusts the mech angle and the top one locks the linkage. The quickest way to set these up is to loosen off both lock screws and set the adjusters to tilt the mechs downwards making sure the mech lever is set fully on. Now turn the adjuster to lift the mech upwards until you start feeling a little resistance. At this point tighten the lock screw. Repeat for the other side. Now when you flip the lever up to engage the snare wires fully you can be sure that they are. If you have to replace the linkage as shown on the right make a note of the direction the pivot point is facing with the wires set to off. You'll know if you got it wrong when reassembled because as one mech comes up the other will go down!!! Finally check you have the correct bottom hoop:
B - 70's Supra
C - Early 60's COB Supra type (extended gate but narrower and squarer profile than A)