I made more progress on the Europa frame last night. Removed the entire
gearchange, speedometer cable, swaybar and lower front closing plate.
I think I have figured out the main problem with the gearchange. I will be
putting in a heim joint to fix the problems with the departed rubber bushing on
the top of the gearbox, thanks to Steve Valin's fine advice. But that is not
the real problem.
95% of the guess-a-gear characteristic of this system is at the junction of the
bottom end of the gear lever and the first horizontal tube that goes back.
Without going into the rest of the linkage (trust me, Rube Goldberg would be
proud), here is what this part does. The bottom of the lever is a simple tang
with a hole in it. The tube has a clevis on the end. The lever tang fits in
the clevis and a bolt (horizontal and across the car) goes through them both.
The tube moves back and forth (end movement) to move from neutral into the
gears. This works just fine.
As the lever is moved side-to-side, the front of the tube moves side-to-side.
This motion is (and is supposed to be) irrelevant to the gearbox. The relevant
motion is the ROTATION of the tube, which is supposed to move the selector
from one gate to another. This tang-and-clevis is not up to it.
The problem: The clevis is supposed to have some spacer washers in it. They
are not there. The whole assembly is worn, and the tang is bent. The result
is that considerable sideways motion of the lever results in no rotation at
all. Since there is a good locating spring in the gearbox, you always wind up
in 3rd or 4th instead of 1st or 2nd. The locating spring for the reverse gate
(reverse is next to 4th) is even stronger, so if you want to back up you get
out and push. This actually makes sense, as at least you can SEE that way.
I believe that this is weak design point. Even if it is bought up to as-new
spec, it will be inadequate. The present design relies on the fit of the tang
in the clevis, and the whole contact area is only about 3/4" high. I think
that this allows too much leverage advantage. I believe what is needed is a
wider base.
The proposed solution: The lever could have the tang removed. A wide clevis,
maybe 2.5" on the inside, can be welded in. Check the clearance to the coolant
tubes on the right of the tunnel. For ease of assembly, a 5/16" Nylock nut
could be spot-welded to the right side. There is room to weld in triangle
gussets. The tube gets a 2.5" long tube welded across the end, with a 5/16"
ID. This is also gusseted. After the tube is wrestled into the tunnel, the
lever with suitable mounting flange, is put in through the oval access hole and
mounted. The tube is introduced to the clevis and a 5/16" bolt secures them.
I have to be able to do this part with only my left hand. The 5/16" bolt
should be a regular Grade 2, so it will be a wear part. I think that can be
replaced from the passenger seat with the body on. Side-to-side play in the
clevis should be irrelevant. Wear in the tube should not be a big factor. I
would like to put a Zerk in it, but it is so hard to reach, I would find it
hard to grease it anyway.
OK, all you Britcar engineers, shoot holes in my theory for me. I really don't
want to be taking this whole car apart again!
The sway bar removal showed me something. The end mounts are actually studs
welded onto the bottom rings of the coil-over units. The right one was bent
back quite a bit. One of the previous owners must have driven over something.
Don't ever drive over anything in a Lotus! I am not going to try to
straighten it. I think it is a Koni, and I don't want to wreck it.
Phil Ethier, THE RIGHT LINE, 672 Orleans Street, Saint Paul, MN 55107-2676
h (612) 224-3105 lotus@pnet51.orb.mn.org
w (612) 298-5324 phile@pwcs.stpaul.gov (list goes here)
"The workingman's GT-40" - Anthony Colin Bruce Chapman
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