1966 Toronado transmission problems!

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classicarsva
Posts: 5
Joined: Mon Jan 22, 2018 5:16 pm
TOA Membership Number: 1305
Years Owned: 1966 toronado deluxe

1966 Toronado transmission problems!

Postby classicarsva » Sat Jun 30, 2018 2:48 pm

Hi Guys,
I purchased a very nice older restoration that had not been used much since work was stopped.
It has 80,840 miles and looks, runs and drives very nice EXCEPT!! The transmission will not upshift automatically. From a stop, it starts forward in DRIVE. It’s like a manual trans being stuck in 4 gear. I am a retired restoration mechanic and very familiar with older cars which have sat around so,

Here’s what I know or have done:
1) Oil level is clean and full when hot in park.
2) Trans will start in low and upshift just fine using manual shifter on column!!
3) Reverse works as it should.
4) I removed non-functional factory kickdown switch assy. from engine and installed Bruce Roe’s electronic switch and 1968 gas pedal assy. Switch pitch and kickdown now work great!
5) I replaced the vacuum modulator and confirmed 15-18 units of vacuum at the transmission.
6) I removed the Governor and confirmed the plastic gear is in good condition.
7) Cruising along at 60-70, the car drives and feels great! I am stumped!!! Help?

I am not familiar enough with this transmission or TH-400’s in general so if anybody has a suggestion or direction for me to try, I’m all ears. Failing that, does anyone know of a transmission shop in central Virginia who has the knowledge to R&R and correctly rebuild a Toronado transmission?

Thanks,
Garland Gentry #1305
(540) 642-6335 (cell and text)
Culpeper, VA

bcroe
Posts: 194
Joined: Thu Nov 15, 2012 12:25 pm
TOA Membership Number: 378
Years Owned: 79 Toronado or Eldorado

1966 Toronado transmission problems!

Postby bcroe » Sun Jul 01, 2018 11:27 am

So the car starts in drive, not the usual problems of slipping or staying in low? My
first guess is the governor is telling the trans to upshift, make sure its seated
properly after any service (not so easy to do). Or try another governor.

Next suspect is the valve body. Since the trans can be shifted into any gear
manually, the rotating parts may be OK. Bruce Roe

classicarsva
Posts: 5
Joined: Mon Jan 22, 2018 5:16 pm
TOA Membership Number: 1305
Years Owned: 1966 toronado deluxe

Re: 1966 Toronado transmission problems!

Postby classicarsva » Mon Jul 02, 2018 8:26 am

Hi Bruce,
Though I could not figure out how to remove the governor weights from the "cup" housing, they seemed to move freely and the valve moved up and down smoothly. Do I assume correctly that the shaft orientation makes no difference
as long as you get the plastic tooth gear to mesh properly?
You are correct, NO upshifts to any gear. Starts forward in drive and you can feel the strain of the transmission trying to move 5000 lbs! Downshift with the Kickdown switch works correctly with no hesitation.
Even though I replaced the Vacuum Modulator valve, is it possible to remove the pushrod in the transmission case to be sure it and the internal valve are clean and moving smoothly? if so, how?
I assume the main valve body can be removed by dropping the pan and leaving the trans in place on the car. Can any transmission shop rebuild these or are rebuilt ones available (for TH-425 !!)?
Thanks or your help Bruce. Love your electronic switch!
Take Care,
Garland Gentry

bcroe
Posts: 194
Joined: Thu Nov 15, 2012 12:25 pm
TOA Membership Number: 378
Years Owned: 79 Toronado or Eldorado

1966 Toronado transmission problems!

Postby bcroe » Mon Jul 02, 2018 10:09 am

classicarsva wrote:Hi Bruce,
Though I could not figure out how to remove the governor weights from the "cup" housing, they seemed to move freely and the valve moved up and down smoothly. Do I assume correctly that the shaft orientation makes no difference
as long as you get the plastic tooth gear to mesh properly?
You are correct, NO upshifts to any gear. Starts forward in drive and you can feel the strain of the transmission trying to move 5000 lbs! Downshift with the Kickdown switch works correctly with no hesitation.
Even though I replaced the Vacuum Modulator valve, is it possible to remove the pushrod in the transmission case to be sure it and the internal valve are clean and moving smoothly? if so, how?
I assume the main valve body can be removed by dropping the pan and leaving the trans in place on the car. Can any transmission shop rebuild these or are rebuilt ones available (for TH-425 !!)?
Thanks or your help Bruce. Love your electronic switch!
Take Care, Garland Gentry


No alignment req for the governor, but with that flat rubber seal its hard to
get it properly sealed. I can't get mine apart either, keep thinking about a
custom outer case so I could get in for tuning. Its likely OK.

When the Vac Mod is removed (and a quart of fluid spills out), there is a
moving valve just inside, which should easily slide straight out given
enough clearance in your car. The valve body and restrictor plate on a
switch pitch 66-67 are different from later years. If you had a spare and
could go through it, I think it could be swapped for comparison using guide
pins and a couple other tricks. Only done it on a TH400 here. Not having a
spare means disabling the car while going through this unit. I expect a
problem there since all gears work in some modes, but I am not an expert
on all 400/425 failure modes. Maybe some research could turn this up.

Here at some point I jerk the trans and put in my backup, not so easy if
you don't have the right equipment. Others likely will go to a shop,
who will have no concept of switch pitch. Put in writing that this feature
must be retained as before.

Glad the switch Pitch Controller is doing the job for you, it would be even harder
to get started without it. good luck, Bruce Roe


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