temperature sending

[dmsfrr]

the speedometer cable and the gear are new , when I pass the 1st gear, the car begin going, the speedometer indicates the maximum and stay like this,when I pass the return he go back to zero....
here is the problem

Just guessing here...
If the transmission isn't original to the car could the speedometer drive gear in the tailshaft be that much different? And if it was, wouldn't it ruin the plastic gear on the lower end of the speedo cable?
Or,
Is it more likely an internal / mechanical problem in the speedometer head?
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[56yblock]

maybe you don't understand what i said it's not easy for me to explain
i post the pic of the part that i've put and it was that missing
i think this part it's not fit with the gearbox

 

[40cpe]

If I'm understanding this correctly, the speedometer goes to max speed when the vehicle starts rolling and goes back to zero when stopped. This won't be a gear or cable problem in itself. This is in the speedo head. The driven gear was removed because of the speedo head problem.

 

[56yblock]

if i understand that what you say, i must to fix or to change my speedometer

 

[40cpe]

Yes, Oui

 

[56yblock]

i saw on the net, there's 4 models for 1956 ford driver gear speedometer 19,20,21,22 teeth, mine it"s 22
how can i know which one is fit for mine?

 

[dmsfrr]

... when I pass the 1st gear, the car begin going, the speedometer indicates the maximum and stay like this,when I pass the return he go back to zero....
here is the problem

.... there's 4 models for 1956 ford driver gear speedometer 19,20,21,22 teeth, mine it"s 22
how can i know which one is fit for mine?

The speedometer head will need to be working much better first. Repair or replacement may be necessary. I do not know how they operate internally.
A speedometer shop should be able to inspect & provide a repair estimate for the one you have.
Is it marked in KPH or MPH?

I suppose there is a complicated way to figure it out with a calculator if you know the circumference of the tires, gear ratio of the differential, number of teeth on the drive gear inside the tailshaft, etc. etc.

The way I've done it is to drive a known correct distance (the mile markers on US highways are very handy) and compare the odometer & speedometer readings to the known distance.
Example: if you drive 1 mile at an indicated 60 mph on the speedometer it should take exactly 1 minute. (1 kilometer at 60 kph = 1 minute)
If it takes less than a minute your speedometer is reading too slow, if it takes more than a minute the speedometer is indicating faster than your actual speed.

If I remember correctly, the number of teeth on the driven gear (19 to 22) changes the reading of the speedometer by 5% per tooth. Less teeth will make the speedometer spin slightly faster, more teeth will slow the speedometer.
When these cars were built/new the speedometers tended to read slightly higher than actual speed. You get the perceived thrill but less speeding tickets.

Example: when driving at an indicated speed of 66 mph/kph if you complete a 1 mile/km distance in 1 minute this would tell you the speedometer is reading 10% too fast. So increase the number of teeth on the driven gear on the cable by 2. (if possible)

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[KULTULZ]

The speedo driven gear is selected from charts/listings in the MPC.

You need to know trans type, rear end ratio and tire size.

The MPC listing is in old tire sizes. You would need a tire type conversion chart to determine present day OD of today's tires.

And as mentioned, if it is a CANADIAN car, it is most likely KPH so one would need the CAN MPC.

Or you can pay the big bucks and go to a speedo shop.

 

[56yblock]

the speedometer is marked in mph from 0 to 120 like yours i think.....
well the size of driver gear there"s not much difference and it should work anyway
i'll try to found a speedometer.....
thanks for help me

 

[dmsfrr]

Finding a speedometer & gauge repair shop near you may or may not be difficult. If you belong to or can find an American car owners club anywhere near you ask for their assistance.
Being in mph, a good used replacement (if needed) will be easier and much less expensive to find than the export/kph version.

Good luck with your search.

PS: I've seen other owners comment of speedometer problems that were solved with a good cleaning and lubrication. It's worth a try.
Some components were never designed to last this long and need a bit of extra help.
During the time our old cars were built their average life expectancy was about 10 or maybe 15 years.
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[KULTULZ]

do you think if i buy 57 t bird (the small) and it works with my 56 gauge ?
or i must change the gauge?

IMO- The easiest way to go about it is to change the adapter bushing on the cyl head to accept the 56 sending unit to be compatible with the vehicle wiring system. It is a 12V car, correct? Some very early 56 models were still 6V.

ADAPT- Water Temp Ind Sensor - B4A 10911-A 3-8in

Below is how to go about changing the adapter and expansion plug on the opposite head-

Hope the copies are readable.

This has to be done when replacing service heads or take-off heads. It is much simpler (IMO) than juggling between different vehicle wiring systems hoping to make the gauge operational.

 

[56yblock]

i just received the 57 sending water gauge i'll try later....

 

[dmsfrr]

This has to be done when replacing service heads or take-off heads. It is much simpler (IMO) than juggling between different vehicle wiring systems hoping to make the gauge operational.

Yes, changing the pressed-in Temp sensor bushing is not really a do-it-yourself project. The machine shop that rebuilt my 292 would have done it at my request but would not guarantee it would stay sealed, due to the receiving hole likely being too corroded after 60+ yrs.

Option A... since the existing temp sensor in the head is the '57+ version, replacing the '56 (full-sized car) temp gauge in the dashboard with a look-alike '57 T-Bird gauge and adding the gauge voltage regulator is one way to do it. A rebuilt '57 gauge sells for about $130 plus a core return charge, and not including the gauge voltage regulator.

Option B... change the Temp sensor in the head to the new/replacement '56 version you already have(?) to match the '56 dash gauge in the car. This does require a 9/16 inch drill bit and a tapered 3/8 inch "pipe thread" tap to re-thread the bushing.

Either of these options 'assumes' that the existing Sensor or Gauge in the car could work correctly if they are connected to electrically matching parts. This is Not a safe assumption without testing those parts.
A '56 temperature gauge should have a resistance of 38 to 40 ohms if I'm reading this parts catalog right. You could also connect an ohm meter to the temp sensor hot & cold but I don't know what it should read, or how it functions internally.

A few cents worth of stray thoughts...
Drilling and re-threading the Temp sensor bushing wasn't as difficult as I expected. And there wasn't an option to use a gauge that would match the (smaller/'57+) sensor that was in the head. But it would have been more difficult if the engine had the intake manifold installed.

If you still have the new (larger/uninstalled) '56 temp sensor... I hired a 'car guy' plumber to come over with the drills & a pipe-thread tap. He re-cut the smaller Temp bushing on my engine, it wasn't too expensive. In hindsight I could have bought the drill bit & tap for slightly less and done the work myself. Approx $50.

Looking in a Hill's Thunderbird '55/'57 parts catalog... you can buy: a new '57 temp sensor, a rebuilt '57 Temp gauge, and a new gauge voltage regulator for about $200. With the exception of adding the gauge voltage regulator, they should be 'bolt-in'/direct replacement parts.
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[KULTULZ]

Yes, changing the pressed-in Temp sensor bushing is not really a do-it-yourself project. The machine shop that rebuilt my 292 would have done it at my request but would not guarantee it would stay sealed, due to the receiving hole likely being too corroded after 60+ yrs.

Not to be argumentative, but if a person can change a water pump, he has the basic skill to replace the adapter. Same as an expansion plug.

The MANUAL shows Special Service Tools usage, but common tools can be substituted. Juggling different year electrical system parts and hoping for the best is a $$$ gamble.

Now, with that being said, your example of re-threading is great (small to large). Never thought of that (and I am old).

A few cents worth of stray thoughts...

Drilling and re-threading the Temp sensor bushing wasn't as difficult as I expected. And there wasn't an option to use a gauge that would match the (smaller/'57+) sensor that was in the head. But it would have been more difficult if the engine had the intake manifold installed.

If you still have the new (larger/uninstalled) '56 temp sensor... I hired a 'car guy' plumber to come over with the drills & a pipe-thread tap. He re-cut the smaller Temp bushing on my engine, it wasn't too expensive. In hindsight I could have bought the drill bit & tap for slightly less and done the work myself. Approx $50.

 

[56yblock]

hello guys i've changed the temperature sending by the new 57 tbird and the gauge don't works, i've check the wiring it's correct, i think the gauge is dead
do you know if i can replaced by a modern gauge with the same wiring?

 

[dmsfrr]

hello guys i've changed the temperature sending by the new 57 tbird and the gauge don't works, i've check the wiring it's correct, i think the gauge is dead
do you know if i can replaced by a modern gauge with the same wiring?

.....
Either of these options 'assumes' that the existing Sensor or Gauge in the car could work correctly if they are connected to electrically matching parts. This is Not a safe assumption without testing those parts.

You can test the gauge by checking that it has 12v power from the Ignition switch.
IF it does...
test again by temporarily connecting the other gauge terminal (the one that goes to the sensor wire) to bare metal on the body of the car and the gauge needle should move all the way across the dial.
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[56yblock]

i've disconnected the wire from sender and i put it on the body car with the contact on, but there nothing

on the gauge, it's written 12 v on the back

 

[dmsfrr]

hello guys i've changed the temperature sending by the new 57 tbird and the gauge don't works, i've check the wiring it's correct, i think the gauge is dead
do you know if i can replaced by a modern gauge with the same wiring?

Do you have a voltmeter or 12 volt test light?
Make sure there is 12 volt power going to the gauge from the Ignition switch.

If the gauge does not have 12v power to it you have to fix that first.

With the key switch ON ...
test again by temporarily connecting a jumper wire from the other gauge terminal (the one that goes to the sensor wire) to bare metal on the body of the car. The gauge needle should move all the way across the dial.
The reason to test from the terminal on the gauge (that goes to the sensor) directly to body-ground, is in case the wire from the gauge to the sensor is broken somewhere.

IF the gauge has power to it and all the wiring is ok (test it first) the gauge may work by itself, but not read the temperature correctly, because...

An original '56 temperature gauge in the dashboard should not work correctly when connected to a '57 temperature sensor in the head. The Temp & Fuel gauge electrical function was upgraded in '57 and is not the same as '56.

In this case, you will need to change the gauge in the dashboard to one for a '57 Thunderbird, and add a ('57+) gauge voltage regulator into the 12v power wiring to the Temp gauge.

OR... install an aftermarket temperature sensor and gauge into the car.

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