Fordomatic late shifting ('57 thunderbird)

[dmsfrr]

Originally Posted by yblock57

. . .
I went ahead and removed the piece of linkage from the accelerator pedal that goes through the firewall and measured and took a few pics. If anyone has one I can compare mine to, that would be great. Not sure if the curve in it is correct or not — it doesn't appear bent to the naked eye. I don't want to flatten that curve in a vise if it is indeed correct and the problem is elsewhere. Tip to tip is 5 7/8"
Nothing else in the setup looks bent or twisted.
Thanks!

I measured the one out of my '57 and also got 5 & 7/8", maybe 15/16.
Also looked in two different restoration parts catalogs and the pedal rod (part # 9727) is the same for all three years, both auto and manual trans.

Not sure if or why it might too short but maybe it's the adjustable rod (yellow arrows) between the manifold bellcrank and the double L shaped throttle lever on the firewall.
With the drill bit thru that alignment hole, if the threaded adjustment rod were longer then it would push the gas pedal higher off the floor.
.

[yblock57]

Sal & dmsfrr —

Thanks very much for the input. Good to know one piece of the puzzle is ok.

I had thought about 'tweaking' the firewall piece and may end up having to do it. Before I do, I wanted to see if anyone had another threaded rod (dmsfrr referred to) that adjusts pedal height that I could compare mine to. Went ahead and removed and got some measurements.

Overall length (fully extended) is 5 1/4". This only gives me approx. 3" pedal height. If all the catalogs list this for 55-57 then maybe this is the correct one. Just wanted to verify before I bend things.


Again, thanks for everyone's help. This is one of the best source of info on these cars out there.

[dmsfrr]

Originally Posted by yblock57

Sal & dmsfrr —
Thanks very much for the input. Good to know one piece of the puzzle is ok.

I had thought about 'tweaking' the firewall piece and may end up having to do it. Before I do, I wanted to see if anyone had another threaded rod (dmsfrr referred to) that adjusts pedal height that I could compare mine to. Went ahead and removed and got some measurements.

Overall length (fully extended) is 5 1/4". This only gives me approx. 3" pedal height. If all the catalogs list this for 55-57 then maybe this is the correct one. Just wanted to verify before I bend things.

Again, thanks for everyone's help. This is one of the best source of info on these cars out there.

That threaded pedal adjustment link at the back of the 'mousetrap' comes in three versions, for '55, '56 and '57.

Part # 9784 - A, B or C for the three different years, in that order. The '55 version may be the longest?
They are on page 33 in a Casco catalog, or page 70 in the Hill's catalog. $50 to $60 depending on the version.
I don't understand why a part that appears to be and should be 'correct' won't give you the adjustment needed. Perhaps you can create a temporary part with a 'better' length and see if it works before doing something more permanent.
If there's a local hot-rod shop near you they may have some pieces to work from.

Mine is the same way, that adjustment link seems too short. But I wrote it off to having '57 linkage, intake manif & carburetor in a '55 that originally used different hardware. So I re-created a slightly different version of the adjustment procedure, without using the 1/4 inch 'alignment tool', drill bit, screwdriver shaft, etc.
So far it's working much better than it was. (but I have nothing else to compare it to)

[KULTULZ]

Originally Posted by dmsfrr

Mine is the same way, that adjustment link seems too short. But I wrote it off to having '57 linkage, intake manif & carburetor in a '55 that originally used different hardware. So I re-created a slightly different version of the adjustment procedure, without using the 1/4 inch 'alignment tool', drill bit, screwdriver shaft, etc.

So far it's working much better than it was. (but I have nothing else to compare it to)

Key statement above ...

Plus, if the trans is not original, it may take different pressure readings at different times (calibration) (using full diagnostic sequence(s). One needs to positively ID the TRANS and if anything varies consider a previous repair/modification may alter the test results.

[yblock57]

Originally Posted by dmsfrr

That threaded pedal adjustment link at the back of the 'mousetrap' comes in three versions, for '55, '56 and '57.

Part # 9784 - A, B or C for the three different years, in that order. The '55 version may be the longest?
They are on page 33 in a Casco catalog, or page 70 in the Hill's catalog. $50 to $60 depending on the version.
I don't understand why a part that appears to be and should be 'correct' won't give you the adjustment needed. Perhaps you can create a temporary part with a 'better' length and see if it works before doing something more permanent.
If there's a local hot-rod shop near you they may have some pieces to work from.

Mine is the same way, that adjustment link seems too short. But I wrote it off to having '57 linkage, intake manif & carburetor in a '55 that originally used different hardware. So I re-created a slightly different version of the adjustment procedure, without using the 1/4 inch 'alignment tool', drill bit, screwdriver shaft, etc.
So far it's working much better than it was. (but I have nothing else to compare it to)

dmsfrr — Good info, thanks. What did you do in your adjustment steps to get things working right? Did you get a different throttle rod going to the carb? Did you extend the pedal rod as long as it would go?

I have a friend with a '57 bird who's going to drive over this afternoon and let me measure the pieces in question, so that should help shed some light on this stuff.

Thanks

[dmsfrr]

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Originally Posted by yblock57

dmsfrr — Good info, thanks. What did you do in your adjustment steps to get things working right? Did you get a different throttle rod going to the carb? Did you extend the pedal rod as long as it would go?
I have a friend with a '57 bird who's going to drive over this afternoon and let me measure the pieces in question, so that should help shed some light on this stuff.
Thanks

Ok... this certainly isn't the official way and will not stay how it currently is when a better idea comes along...
It's just what I've done so far, because the way it was before was really awful and I didn't want to cook the transmission.

I disconnected both the adjustable rod to the carburetor throttle lever and the clevis at the top of the transmission rod from the throttle bell-crank assembly that mounts to the intake manifold.
This allowed the throttle return spring to press the bottom end of the firewall throttle lever against the firewall (photo 1) raising the pedal as high off the floor as it would go. (approx 4" from the firewall to the top front side of the pedal)
The spot on the firewall where the lever hits is about 2 inches above the hole where the pedal rod comes thru the firewall. I got a 1/4" thick x 3/4" dia self-stick felt pad and stuck it to that spot on the firewall so the throttle lever can rest against it.

The (oem '55 ?) throttle position rod down to the transmission may also be short on this car so I adjusted the pedal-position threaded link at the back of the bell-crank (photo 2) to let the lever coming thru the bell-crank assembly reach the rod when it's carefully pulled all the way up. (photo 3)

If I'm not mistaken, the 'book' procedure on connecting the adjustable clevis at the top of the transmission rod has you carefully pull the rod up until it stops then adjust the clevis to align with its lever on the throttle bell-crank, then unscrew it an additional three full turns and connect it. So I did that. The clevis adjustment can be fine-tuned from this generic starting position.

Then making sure the fast idle cam was disengaged, I installed the threaded rod from the throttle lever on the carb back to the bell-crank assembly, adjusting its length as needed, plus about one extra turn in length.
Somehow it all fit and seems to work much better than before, and I'm keeping my fingers crossed.

Something I have not tried yet is to force a downshift by flooring the gas pedal, I need to be more comfortable with how well it's working so far. (but haven't driven the car since March when lock-downs started happening and it's already overdue for an oil change)

[yblock57]

dmsfrr —

Thanks for the detailed description. That helped me a lot.

After looking at pics on here and my friend's '57 and comparing setups, the conclusion was my double-L rod on the firewall was bent... slightly. I removed it from the car and mounted it on my workbench. Was expecting a battle to get any bending action, but it moved surprisingly easy.

Got lucky as I bent it it just the right amount the first time. Verified 4 7/8" pedal height with the 1/4 drill bit in the bell crank. Adjusted the rod going to the carburetor and presto — everything works as advertised. No more binding, and I get full throttle with the pedal — at least everything up top is moving the way it should... we'll see how it goes with the throttle rod once the valve body goes back in.

https://youtu.be/3yTgu1UNZI4

Now it's just a matter of getting the valve body back in the transmission and verifying throttle rod travel and getting pressures set correctly.

Thanks to all who've chimed in and helped. I'll keep y'all posted on how this turns out.

[dmsfrr]

Great, glad I could help a little.

After just now double checking the actual pedal height in this car against the diagram on page 2-89 of the '57 shop manual it seems the pedal may be a bit too high.
Figure 105 shows a distance of 3.10" from the bump-stop on the floor to the 'shoe leather' surface of the gas pedal, although the diagrams look to be for the 'full-sized' cars not T-bird. (photo 3 in reply #75 below)
Measuring that distance I got approx 3 & 5/8", so the pedal could be about 1/2" too high, assuming it matters at this point.

In an earlier comment in this thread you mentioned "The only thing I couldn't get in spec was the accelerator pedal height. Book says '57 thunderbird should be 4 7/8". ..."
Since the diagrams in the shop manual I have may not have the correct T-Bird diagrams, which book did that measurement come from? So I can do a better job on this one next time I tinker with it.
.

[yblock57]

Originally Posted by dmsfrr

Great, glad I could help a little.

After just now double checking the actual pedal height in this car against the diagram on page 2-89 of the '57 shop manual it seems the pedal may be a bit too high.
Figure 105 shows a distance of 3.10" from the bump-stop on the floor to the 'shoe leather' surface of the gas pedal, although the diagrams look to be for the 'full-sized' cars not T-bird.
Measuring that distance I got approx 3 & 5/8", so the pedal could be about 1/2" too high, assuming it matters at this point.

In an earlier comment in this thread you mentioned "The only thing I couldn't get in spec was the accelerator pedal height. Book says '57 thunderbird should be 4 7/8". ..."
Since the diagrams in the shop manual I have may not have the correct T-Bird diagrams, which book did that measurement come from? So I can do a better job on this one next time I tinker with it.

It is confusing as 4 7/8" is a very high pedal. It's almost standing up straight. Since I had to bend my bracket anyway, I tried to get it as close to what the book says as possible.

My buddy's thunderbird's pedal was also only about 3 1/2" off the floor — for what it's worth.

Here's a pic of the table showing different pedal heights in the 56/57 fordomatic manual.

[dmsfrr]

Originally Posted by yblock57

It is confusing as 4 7/8" is a very high pedal. It's almost standing up straight. Since I had to bend my bracket anyway, I tried to get it as close to what the book says as possible.

My buddy's thunderbird's pedal was also only about 3 1/2" off the floor — for what it's worth.

Here's a pic of the table showing different pedal heights in the 56/57 fordomatic manual.

Is there a diagram that goes with measurements table? Showing the points the measurements relate to?
Thanks

[yblock57]

Originally Posted by dmsfrr

Is there a diagram that goes with measurements table? Showing the points the measurements relate to?
Thanks

It doesn't get too specific other than saying "measure from the floor pan to the pedal." This is the only diagram that shows a typical setup (with overdrive).

I measured from the lowest point on the floor to the highest point on the pedal to get my 4 7/8".

Hope this helps.

[KULTULZ]

There should be a throttle stop on the toeboard -

[yblock57]

Originally Posted by KULTULZ

There should be a throttle stop on the toeboard -

I saw that illustration in the manual but am not sure what 'stop' there would be. All 4 of my cars do not have anything under the pedal — just carpet.

Have a pic of the stop in question?

Thanks.

[KULTULZ]

Originally Posted by yblock57

I saw that illustration in the manual but am not sure what 'stop' there would be. All 4 of my cars do not have anything under the pedal — just carpet.

Have a pic of the stop in question?

Thanks.

Sorry, no I do not.

But dmsfrr does -

[dmsfrr]

Originally Posted by yblock57

I saw that illustration in the manual but am not sure what 'stop' there would be. All 4 of my cars do not have anything under the pedal — just carpet.

Have a pic of the stop in question?
Thanks.

A couple dirty 'before' pictures.
There's a bump in the floor under the pedal (photo 1) for mounting the overdrive kickdown switch (photo 2) if the car has a 3spd OD trans. It's about 5/8 high. I'm guessing we can ignore it???
.

[yblock57]

Originally Posted by dmsfrr

A couple dirty 'before' pictures. There's a bump in the floor under the pedal for mounting the overdrive kickdown switch, if the car has a 3spd OD trans.
.

Thanks, dmsfrr. Pics help a ton.

Looks like you had your car torn down pretty far. Is it a 292 or 312?

[dmsfrr]

Originally Posted by yblock57

Thanks, dmsfrr. Pics help a ton.
Looks like you had your car torn down pretty far. Is it a 292 or 312?

You're welcome. Photos are easy and no problem...

There are two T-Birds, a not-quite-original red '55 and a nearly original yellow '57, with a black engine compartment.
The '55 has a rebuilt 6 month newer 292 (since the original engine was gone) with '58 heads & '57 intake, carb, distributor and '55 air cooled Fordomatic transmission... also rebuilt front & rear suspension. The car is mostly done with the major exception of the dash gauges needing to be repaired/replaced.

The '57 I semi-recently bought and it's currently all torn down to be repainted and have the original 312 engine and 3spd OD trans rebuilt.

There are a few photos at this link....
https://www.fordbarn.com/forum/album.php?u=24155
.

[Daves55Sedan]

Lets approach it this way, without the need to bend anything.
According to the '56 Fordomatic shop manual, your pedal height should be 4-1/4" from the floor (check your '57 Fordomatic shop manual to make sure it is the same).
DISCONNECT the carburator connecting link from the carburator and DISCONNECT one end of the accellerator connecting link from the bellcrank on the intake manifold.
Doing this allows your bellcrank to be in a floating position.
Take a 1/4" diameter doll-pin or drill bit and insert it through alignment holes in the bellcrank to lock the bellcrank in idle position.
Prop the gas pedal up off the floor with wooden blocks and wedges until it is at the specified height off the floor. Pulling the gas pedal further off the floor will pull the firewall bellcrank arm closer to the firewall. (You WANT that to happen).
NOWWWW, inspect your accellerator connecting link and see how much you need to modify its LENGTH. It is adjustable by loosening the locknut on the threaded rod in the middle. Rotate the threaded rod and fit (as many times as needed) to get the end clevis of the accellerator connecting link to go into the bellcrank freely. When that has been accomplished, tighten the locknut on the treaded rod and re-install the clip that holds the clevis to the bellcrank.
Nowwww go to the carburator connecting link and adjust it (similar to the way the accell link is adjusted) so that the length of the assembly places your carburator at idle speed. NOTICE, if the carb has a Fordomatic anti-stall dashpot, you MUST hold the carb throttle lever at full stop closed while adjusting the carb link to the proper length to achieve idle speed.
Pull the drill bit out of the intake bellcrank and watch to see if the holes become mis-aligned. If they do, you may have a worn bellcrank and need further adjustment.
Now you are ready to adjust the Fordomatic passing gear link in accordance with the Fordomatic shop manual. There should be no need to bend anything.
Yes the rod connected to the back of the gas pedal is factory curved due to the fulcrum point being so far away from the hole thru the firewall. If you attempt to straighten the gas pedal rod, it will likely SCRAPE against the hole through the firewall.
When all finished, make sure you remove the temporary drill bit from the intake bellcrank and remove the wooden blocks under the gas pedal.

[KULTULZ]

Originally Posted by yblock57

I saw that illustration in the manual but am not sure what 'stop' there would be. All 4 of my cars do not have anything under the pedal — just carpet.

Have a pic of the stop in question?

Thanks.

dmsfrr shows the photo of the stop. This is where you would measure from for pedal height.

[KULTULZ]

Originally Posted by Daves55Sedan

Now you are ready to adjust the Fordomatic passing gear link in accordance with the Fordomatic shop manual.

There is no PASSING GEAR LINK. It is called a THROTTLE CONTROL VALVE ROD. Everything operates off this rod.