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67 downshift switch fixed!

Started by TomB, May 11, 2022, 06:46:11 AM

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TomB

Switch was mess, kickdown resulted in abrubt stalling of the engine. NOS switches seem to have vanished. So decided to open it, just for fun, expecting to find a bunch electric rubble and broken plastic.
Grinded the rivets, and with tiny diskgrinder I managed to separate the two halfs. Minor damage, still workable.

Inside was extremely simple, just full of gunk, cleaned it, polished the contacts and the whole thing together again. 1 hour of work.

Turn signal switch T&T 1967 is next...

Matti R

Great Tom,
I repaired the same for my 67. Do you a photo with all inside parts separated? I would like to compare to what I found inside.
Thanks
Best regards,
Matti
CLC #33333
67 DeVille convertible Sudan beige
79 Seville
64 Sedan DeVille
66 Calais Coupe

TomB

Hereby a picture of the individual parts. I did not find the two screws...probably alternative way to close it instead of the rivets? Let me know what you think.

Cheers, Tom

bcroe

Hope it holds up, looks like a few cracks started. 
Bruce Roe

TomB

Hereby the picture, uploading went wrong. I hope that the two parts that make a circle, should indeed be two parts.....

Matti R

Thanks Tom,
I have 3 pcs there where you have 2. So mine is a bit broken.
Do you have the wire with supressor connected to coil bracket? Does your switch pitch work now like it should?
Best regards,
Matti
CLC #33333
67 DeVille convertible Sudan beige
79 Seville
64 Sedan DeVille
66 Calais Coupe

TomB

Yes wiring is in place, looking for the courage  to connect it, on a quiet early sunday morning when the highway is empty....

TJ Hopland

That's one of 100's of items on an old car that you wonder are you better off to risk minimal damage to 'service' a 'non serviceable' item vs. risk it being damaged beyond repair if you just ignore it as long as its working? 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

bcroe

Quote from: TJ HoplandThat's one of 100's of items on an old car that you wonder are you better off to risk minimal damage to 'service' a 'non serviceable' item vs. risk it being damaged beyond repair if you just ignore it as long as its working?

That part when working, will not do much for you.  A
diode from the brake switch (already in some car models)
and a very simple 2 wire kickdown do almost the same.  I
built a superior replacement decades ago.  Bruce Roe

TomB

Hi Bruce, I take it from you that the fun of fixing the switch is probably short lived, if at all. Do you have some more detailed description anywhere? Sounds your solution make more sense than my hobby-ing.

Cheers

Tom

bcroe

Quote from: TomB. Hi Bruce, I take it from you that the fun of fixing the switch is probably short lived, if at all. Do you have some more detailed description anywhere? Sounds your solution make more sense than my hobby-ing. Cheers Tom

I started experimenting with switch pitch in 1985.  email me at
bcroe@juno.com

cadillactim

Bruce

Isn't the idea of the switch pitch to give you more torque? It does almost feel like another gear when it is working.

Tim
Tim Groves

"Cadillac Kid" Greg Surfas 15364

The switch pitch refers to the torque converter. When the system is activated it puts the converter into "high stall" either allowing for more slip when stopped in gear at idle or allowing more stall speed under power allowing the engine to operate faster resulting in a higher point on the power curve.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

bcroe

Quote from: cadillactimBruce.   Isn't the idea of the switch pitch to give you more torque? It does almost feel like another gear when it is working.
Tim   

Like the name says, a torque converter changes higher
rpm and lower torque at the input, to higher torque and
lower rpm at the output.  A typical setup gives 2 times the
engine torque at launch, quite an advantage over a simple
gear box.  As rpm increases, the ratio gradually transitions
from 2:1 to 1:1 at high rpm.  So the converter does what
would take 2 gears with a straight gear box and clutch. 

Torque mulitiplication allows a much lower number for the
final drive (axle) ratio, without sacrificing launch performance.
This looks like an overdrive ratio compared to earlier cars, so
you lower engine cruise rpm and fuel consumption.  In the
late 70s axle ratio numbers were lowered even more, some
around 2.2:1 to increase the overdrive benefit, but sacrificing
some of the launch torque.  This can only be taken so far,
because higher torque at lower rpm causes the converter slip
losses to increase.  In the 80s we got 4 speed (overdrive)
transmissions with lockup torque converters, to eliminate the
slip loss cruising.  These improved fuel economy some more
with lower engine cruising rpm. 

The SWitch Pitch torque converter lets you chose between more
slip and torque multiplication (performance mode), or less
(economy mode).  So instead of a compromise design, it can
give more performance, AND slightly better fuel economy. 
Performance mode at launch will give on the order of 12 to
20% more torque than a fixed converter.  I use this advantage
to take a full second off 0-60 time on my 2.4:1 axle cars. 
The factory setup will only do this at Wide Open Throttle,
to activate the throttle switch.  My cars use the advantage
at any launch, with a delay timer. 

But SWP has more benefit.  Gear shifting is much smoother
if done in converter performance mode.  Factory setup does
this at WOT, a delay timer always does it.  The performance
mode can be used to make the car more responsive in mid
range driving, but the factory setup does not do this. 
Bruce Roe

cadillactim

Bruce

Greg and Bruce, thanks for the input. So at idle the SWP is giving you quicker response when you drive off than at cruising speed, and at WOT you are getting both the SWP quicker response and the lower gear due to the vane positions in the torque converter. Is this correct?
Tim Groves

bcroe

Quote from: cadillactim on May 13, 2022, 07:05:05 PM
Bruce

Greg and Bruce, thanks for the input. So at idle the SWP is giving you quicker response when you drive off than at cruising speed, and at WOT you are getting both the SWP quicker response and the lower gear due to the vane positions in the torque converter. Is this correct?

With the factory setup, the trans will switched to low stall
(economy mode) as soon as you drive off, unless you
are close to WOT.  A timer instead will stay in performance
for any acceleration situation.  Bruce Roe

Matti R

According to 67 FSM it should switch to performance mode at 40˚ throttle position, and kickdown should activate at 60˚ position.
Best regards,
Matti
CLC #33333
67 DeVille convertible Sudan beige
79 Seville
64 Sedan DeVille
66 Calais Coupe