moparmark65
Well-Known Member
Im trying to switch my speedo from Km, ro Mph. Do I need to swap out the speedo gear in the A833 transmission? Are they the same as the 727, A 904 speedo gears?
Switching from Km, to MPH.
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moparmark65
Well-Known Member
They did in mexico! Mine is a mexican built 69 GTS. Also the nexican dart used the 68 ralle dash in the 69.
moparmark65
Well-Known Member
They also did hood mounted tach from factory. Another cool feature!
missing linc
Loose nut behind the wheel
It should be simply a matter of swapping the speedometer assembly with one that has the scale in mph. At least in theory it should be, though I have not actually done it. The gears in the transmission are primarily synchronized to the rear axle ratio.
A Bodies assembled and sold in Europe came with KPH Speedos. Friend in Switzerland had a 66 Barracuda assembed there and had a KPH speedo and other things unique to A bidies assrmbled in Europe
mopowers
Well-Known Member
You could always measure your tire and see which speedometer gear you have. Then reference one of the many charts available to see if you've got the correct gear.
70SwingerGuy
Long Haired Freaky Person
I agree with @missing linc , put in a speedo that has the kmh scale, if your speed is out, adjust your transmission pinion accordingly to tire size and rear gear ratio. Brewers sells the pinions and can help you out if you need it.
BTW, how hard is it to find a speedo from a rally dash in km? Id guess pretty rare
BTW, how hard is it to find a speedo from a rally dash in km? Id guess pretty rare
My son's 70 Duster (Hot Rod Project car) has a KPH speedometer.
I thought it was from in cars sold in Canada (Guess)?
If no one believes me = I will get him to post a picture when he
gets back from racing at Brainard Nationals.
I thought it was from in cars sold in Canada (Guess)?
If no one believes me = I will get him to post a picture when he
gets back from racing at Brainard Nationals.
70SwingerGuy
Long Haired Freaky Person
I believe you! But I wonder if a previous owner put it in cause Canada didnt start its switch to the metric system until 1975
There is a ratio of kpn to mph.
Find out what gear you have in your trans now.
Then use that ratio to get a gear that will slow down the speedo that much. Now you have a 150 mph speedo. Iirc the 67-69 speedos did not have the "MPH" OR "KPH" printed on the speedo anywhere.
Now the problem with this is the odometer will be very wrong from them on, and finding the correct gear size might be impossible
Unless I did my math wrong....
If you have a 38 tooth gear you would need a 23 tooth gear to slow the speedo down to what would read 37 mph (on a mph speedo) to equate to 60 on the KPH speedo.
Current Teeth / 1.609 = new teeth
It gets confusing really fast
Someone check my logic please
Find out what gear you have in your trans now.
Then use that ratio to get a gear that will slow down the speedo that much. Now you have a 150 mph speedo. Iirc the 67-69 speedos did not have the "MPH" OR "KPH" printed on the speedo anywhere.
Now the problem with this is the odometer will be very wrong from them on, and finding the correct gear size might be impossible
Unless I did my math wrong....
If you have a 38 tooth gear you would need a 23 tooth gear to slow the speedo down to what would read 37 mph (on a mph speedo) to equate to 60 on the KPH speedo.
Current Teeth / 1.609 = new teeth
It gets confusing really fast
Someone check my logic please
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Quite likely,
Are the clusters not basically interchangeable (Although slightly different)
up to 76?
moparmark65
Well-Known Member
All good input, and maybe Im overthinking it. My speedo has the trip gauge on it as well. I did find a new face decal set. But thought if I can gauge it correctly, i can learn the compensation. I can also use a gps speedo to figure it out without pulling the rallye cluster which is a cluster in itself!
missing linc
Loose nut behind the wheel
As Dana67Dart mentioned the conversion factor is kmh ÷ 1.609 = mph.
In effect:
60 kmh = 37 mph
50 kmh = 31 mph
100 kmh = 62 mph
etc.
In effect:
60 kmh = 37 mph
50 kmh = 31 mph
100 kmh = 62 mph
etc.
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moparmark65
Well-Known Member
Must be a typo in there somewhere. 50kmh=51mph? That should be more like31 mph. But yes thanks!
I have always thought of it as 1/2 the speed, like 120 KPH is 60 mph
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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The ratio is .62
But there are not enough pinions to make this switch using the MPH speed-o. I tried it.
What you need is a Multiplier/reducer, adapter like the Gear-Vendors unit..
What you do is get a really short cable and drive the unit, the stick your cable on the other end. Presto. If the internal ratio of the unit is not exactly correct, then you change your pinion, by calculating the percent error.
Here is an image I grabbed off the net;
OOPs it won't paste
Here is the link
But there are not enough pinions to make this switch using the MPH speed-o. I tried it.
What you need is a Multiplier/reducer, adapter like the Gear-Vendors unit..
What you do is get a really short cable and drive the unit, the stick your cable on the other end. Presto. If the internal ratio of the unit is not exactly correct, then you change your pinion, by calculating the percent error.
Here is an image I grabbed off the net;
OOPs it won't paste
Here is the link
340six
King Of Bling
I know that Great Lake NOS had piles of um. As I bought some of the later year ones. He sold me some with other NOS parts as he gave me a great package deal on a bunch of stuff I needed and other things I just wanted.
The Slant and some some 318 cars got 200 but most 318 and 340/360 car's received 240.
Sure looks cool in a stock dash.
340six
King Of Bling
.
missing linc
Loose nut behind the wheel
Yup, definite typo, should in fact be 31 mph.
Op has a KPH speedo he needs to slow the input down to make it read 60 when head going 60 mph.
I think the gizmo you posted would be a great way to go if a proper tooth pinion is not available.
Multiply by 0.62 or divide by 1.609 same thing either way you are slowing the input speedometer shaft
Dartnut
Don't hate me because i'm beautiful
I would leave it as is and when you are driving just do the math quickly in your head.
That's what I have to do in reverse to you, because our speed limit signs are in KM/H.
Quickly take the speed on the speedometer and multiply it by 0.6, and that will give you the rough figure.
So 100 KM/H is roughly 60 MP/H. 60 is 40, and so on.
Or you can use a piece of masking tape and write the conversion number on it, and stick it to the plastic lens on the right place with an arrow cut into the tape...
That's what I have to do in reverse to you, because our speed limit signs are in KM/H.
Quickly take the speed on the speedometer and multiply it by 0.6, and that will give you the rough figure.
So 100 KM/H is roughly 60 MP/H. 60 is 40, and so on.
Or you can use a piece of masking tape and write the conversion number on it, and stick it to the plastic lens on the right place with an arrow cut into the tape...
slantsixdan
=..=
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