Speedometer turtle position

[qmdv]

If you are sitting in the engine compartment and looking to the rear, does the speedometer turtle threaded end face clockwise or counter clockwise. It will bolt on either way but will only work correctly in one direction

[koates]

It points towards your right from the position you are in or to the drivers side of the car in a left hand drive vehicle. Regards, Kevin.

[DavidG]

What year car are you asking about? The answer Kevin provided does not apply to all Ford model years covered by this site.

[qmdv]

Originally Posted by DavidG

What year car are you asking about? The answer Kevin provided does not apply to all Ford model years covered by this site.

It is a 32 with a later shortened rear end. The answer that Kevin gave is not relevant to my question. It should not matter what year you talk about. Question was if you look at it from the front, is it facing clockwise or counter clockwise. Facing left or right is not in the question.

[V8COOPMAN]

This is a 1935 turtle. The cable head faces the driver's side of vehicle. DD

[qmdv]

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Originally Posted by V8COOPMAN

This is a 1935 turtle. The cable head faces the driver's side of vehicle. DD

Looking at it from the front, it is aimed clockwise. So it does not matter what year, they all aim clockwise, right? The shortened driveline I have has the turtle hole on the left side. So I should aim it down

[V8COOPMAN]

Originally Posted by qmdv

Looking at it from the front, it is aimed clockwise. So it does not matter what year, they all aim clockwise, right? The shortened driveline I have has the turtle hole on the left side. So I should aim it down

The torque tube/drive shaft in my picture has also been shortened. We strived to keep the turtle hole in it's original position circumferentially, although I suppose it doesn't really matter if the mounting hole has rotated to some degree. What is important is that the turtle is not pointed in the opposite direction from original, as it will turn the cable backwards. I'd point the cable connection clockwise (looking FROM the front) as you suggest. DD

[koates]

Originally Posted by qmdv

It is a 32 with a later shortened rear end. The answer that Kevin gave is not relevant to my question. It should not matter what year you talk about. Question was if you look at it from the front, is it facing clockwise or counter clockwise. Facing left or right is not in the question.

Well if you had stated in the first place that your car is modified then it would help with a correct answer. If your turtle is on the left side of the torque tube the threaded cable connection would point towards the ground(clockwise if you like). Be aware of ground clearance where the cable curves around as that bend in the cable should not be too tight an angle. Regards, Kevin.

[DavidG]

Clockwise is correct when viewed from the front of the vehicle, whether it is a stock '32 rear end where it is mounted on the bottom of the torque tube or a later rear end, modified or not, where it is mounted on the top of the torque tube as shown in your photo.

[19Fordy]

Here's the stock 1940 turtle position. I added a homemade grease fitting so the universal joint could be lubed from inside the car instead of crawling under the car. Tag should say "lift" off cover.

[Mart]

The long way:
You can work it out yourself from first principles. Then you can work out which way for any application.

Speedo's turn clockwise when viewed from the drivers seat, that is the direction you want the cable to be rotating. This would be anti-clockwise as viewed from the driveshaft end.
To achieve this, Look at the gear on the driveshaft in the photos above. It has a right hand helix. So as the car moves forward the surface at the opening scrolls forwards. (hard to put in words.)

So imagine the turtle gear sitting on that worm gear. If you angle the turtle towards the top of the pic, the forward scrolling would result in a clockwise rotation when viewed from the driveshaft. That's no good as we want anti-clock. So if you put it on pointing down, (towards the USA drivers side) then the rotation would be anti-clock from the driveshaft end, and anti-clock as it enters the BACK of the speedo. When viewed from the front of the speedo you would get the clockwise rotation you need.

While this is easy for me, as I have always been "mechanically minded" as my Gran used to say, I appreciate it might not come naturally to all. But sit sown with a pencil and paper and start doodling and drawing arrows of rotation and it might suddenly ring a bell.

The short way:
If the hole is on the top point the turtle to the left.
If the hole is on the bottom point it to the right.

My left and right are as normal convention which is as viewed from the drivers seat. (not as viewed from the engine bay as in the original post)

Hope this helps.

Mart.

[qmdv]

Thanks. My turtle is mounted on the left of the drive shaft and will be pointing down. Probably get a 90 degree adaptor to get it to point to the right

[Mart]

I just thought of another way of thinking about it based on my post above. The output of the turtle should point in the direction of the driveshaft rotation when the vehicle is in forward motion.

Mart.

[qmdv]

Originally Posted by Mart

I just thought of another way of thinking about it based on my post above. The output of the turtle should point in the direction of the driveshaft rotation when the vehicle is in forward motion.

Mart.

How bout simply counter clockwise when sitting in the front seat. Oh darn, this is no help to the generation of kids that have had all the clocks at home and school replace with digital LOL

[Tinker]

I always thought it can be installed either. But is dependent on cable position.

[V8COOPMAN]

Originally Posted by Tinker

I always thought it can be installed either. But is dependent on cable position.

Try to picture what those two gears really do when mated. When you turn that turtle around, it really will be rotated in the opposite direction. DD

[Tinker]

Just flip the gear in the turtle. On a 38 you can. Maybe wrong year or other. No way they mess otherwise.

[V8COOPMAN]

Originally Posted by Tinker

Just flip the gear in the turtle. On a 38 you can. Maybe wrong year or other. No way they mess otherwise.

Tinker....I know that you can take these things apart. I posted this picture for another 'Barner about a year and a half ago. Turning the gear around leaves the shaft turning in the same direction. Clearly, turning the gear around does NOT reverse the direction that the shaft turns. It's kind'a like a fan blade. You can turn a fan blade around, but the direction the air MOVES will still be the same. You knew THAT, right? DD

[Tinker]

i agree if the blade is in the right direction. If I turned it the other way it'd be fine. gears are dependent on direction. But if you installed the turtle housing reverse and reversed the gears. Gears need to match. mesh. the housing/turtle best to my knowledge is symmetrical.


Maybe we are talking about different years. It is different for the forty then the 38 im guessing. So. the 38 turtle is different, on a 38 they can be installed wrong because you can switch them. my bad.


On a early ford the gears are just held in with the housing/turtle shell.





.

[V8COOPMAN]

Originally Posted by Tinker

i agree if the blade is in the right direction. If I turned it the other way it'd be fine. gears are dependent on direction. But if you installed the turtle housing reverse and reversed the gears. Gears need to match. mesh. the housing/turtle best to my knowledge is symmetrical.


Maybe we are talking about different years. It is different for the forty then the 38 im guessing. So. the 38 turtle is different, on a 38 they can be installed wrong because you can switch them. my bad.


On a early ford the gears are just held in with the housing/turtle shell.

Tinker....In the example below, the green spiral gear perfectly represents the spiral gear on a Ford drive shaft. Consider that it constantly turns in the same direction when the car moves FORWARD. Note the direction that the straight-cut gear turns (representing the TURTLE gear). It should be clear that even if you flip the straight-cut gear on it's shaft, it's shaft will continue to turn in the same direction. DD





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[koates]

Very clever V8 COUPEMAN, but how come the large gear rotates but the centre shaft keyway just jumps clock and anti clock a few degrees ? Tinker, sometimes I have great difficulty understanding your theories. Reread what you have typed. Regards, Kevin.

[51woodie]

Coopman. Where did you find that graphic, and are there more like those? Would be handy to explaining stuff to my Grandsons.

[V8COOPMAN]

Originally Posted by koates

Very clever V8 COUPEMAN, but how come the large gear rotates but the centre shaft keyway just jumps clock and anti clock a few degrees ? Regards, Kevin.

Maybe that would explain why your speedometer needle starts bouncing-around sometimes. Sorry Kevin...I honestly didn't even catch that detail! I just couldn't pass-up that "cheap" opportunity for a laugh! I just grabbed that one off the internet "as is". DD

[V8COOPMAN]

Originally Posted by 51woodie

Coopman. Where did you find that graphic, and are there more like those? Would be handy to explaining stuff to my Grandsons.

51woodie....I COULD tell ya that I created that, but I ain't got near enough smarts to pull that off....yet! Anyway, these sorts of very short, repeating movie-type clips are called "GIF" files. It's a format of sorts, I suppose similar to a single picture "JPG"-type format that we are all used to in taking electronic pictures. There are virtually gazillions of these GIF files all over the internet.


You can pick a subject out of thin air....keep the wording as brief and simple as possible. Last night, I typed "worm gear GIF" into my browser. Hundreds (if not more) of related pictures came-up when I clicked on the underlying "Images" thread. Each of the pictures (IMAGES) will have a "GIF" in a tiny, rectangular box superimposed on each picture. If you use your mouse to move the cursor onto any one of those GIF pictures, the picture (short movie-like clips) will begin playing over and over. You can pick virtually any subject you like to type into your browser with GIF tagged-onto the end, like the worm gear GIF above. How about this one...old biplane GIF ….hit "ENTER", and a ridiculous number of old airplane pics appear, marked with the requisite GIF in the tiny rectangle. Just move your cursor over any of the pictures. That pic will begin moving in some animated manner. NOTE that every now and then, you'll encounter one that is dead...just won't move for squat! When you do put your cursor on any of these GIFs, you can left-click on it and it will almost always get larger.


After I (just now) typed-in old biplane GIF into my browser, a whole boatload of old airplane GIFs came-up. I scrolled thru quite a few until I found one of this old wheel-less seaplane taking-off from a trailer. After that, you can COPY and insert the URL here in a post if you so desire through regular means. The GIF should now be planted and running 'til the end of time, or until the Corona Beer-drinking cooties get ya. Y'all be safe! DD



…...

[V8COOPMAN]

Originally Posted by koates

Very clever V8 COUPEMAN, but how come the large gear rotates but the centre shaft keyway just jumps clock and anti clock a few degrees ?

kevin …...SERIOUSLY, I just realized that since this is a GIF-type image, these images play for a few moments.....and then repeat themselves over and over, infinitely. This gear only begins to make a partial revolution before it re-starts the sequence. So there! DD

[Tinker]

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Originally Posted by koates

Very clever V8 COUPEMAN, but how come the large gear rotates but the centre shaft keyway just jumps clock and anti clock a few degrees ? Tinker, sometimes I have great difficulty understanding your theories. Reread what you have typed. Regards, Kevin.

Kevin, I probably should refrain for posting sometimes. I don't think questions are bad, it's how I learn and sometimes I'm thick.

I see what you are saying v8 coup. The illustration is good but it is missing a 3rd gear that runs to cable. Which would change the direction of rotation if you flip the housing and worm gear.


You can flip the housing by flipping the worm gear, but if you changed the position of the outer shell. the direction of the speedo/cable (3rd gear) would go in the reverse direction.


I believe.