3:07 rear getting the speedo right

Okay, everything you wanted to know about 3:07 speedometers..........
Thanks to everyone I called both companies to recalibrate the speedo, both after all these years dont have the formula to just make the adjustment. Both need you to drive a certain distance , pull the speedo, count revolutions and the whole nine yards. Before I went to that Torture , I gave it one more try...........
Thanks to Dave Welch and Boone, at WELCH JAGUAR , Im done.
They had a completely restored 3:07 speedo, HURRAY! But as we all know the jaguar way ALWAYS has a catch.
The speedo was an early etype unit......Whats the difference?
Everything is the same BUT the lights are BLUE!
Also the outside black ring has a sharp edge compared to a series 2 as its round / smooth the whole way around.
1. Take off the front lense of the new unit, just twist it.... turn over and remove the 2 screws from the back of the unit that hold the cluster in place , swap out the old back from the series 2 which has the green lights........
once the new unit is screwed back into the series 2 back plate replace the front ring and glass from you old series 2.....
There you have it! Also the high beam jewel comes out towards red when lit compared to series 2 which is a dull blue.
My car now runs with 1 mile accurate.........I have larger radial tires. 205/70/15.
Here is the etype part number if you find a complete speedo....
front face reads SN 6322/09
Now like ive said before, you can just plop in a mark2 3.8 overdrive unit.
Those part numbers are SN6317 08 OR SN6317 08A.
The 08a is a newer unit with bars between the trip numbers and more modern spring unit.
Remember though, they only read 140 miles per hour, with the high beam jewel on top......
Also the light behind are BLUE, But if you have no care they will work fine....
A mark 2 speedo you can get for 30 to 150 dollars..
The real etype is around the 400 dollars zone......
Well worth it for me..........
Hope this helps someone fishing at auto jumbles and swap meets..........
Good Luck
GTJOEY1314

Edited on 2013-06-03 23:06:21

Edited on 2013-06-03 21:58:01

Edited on 2013-06-03 21:52:27

Okay, everything you wanted to know about 3:07 speedometers..........
Thanks to everyone I called both companies to recalibrate the speedo, both after all these years dont have the formula to just make the adjustment. Both need you to drive a certain distance , pull the speedo, count revolutions and the whole nine yards. Before I went through that Torture , I gave it one more try...........
Thanks to Dave Welch and Boone, at WELCH JAGUAR , Im done.
They had a completely restored 3:07 speedo, HURRAY! But as we all know the jaguar way ALWAYS has a catch.
The speedo was an early etype unit......Whats the difference?
Everything is the same BUT the lights are BLUE!
Also the outside black ring has a sharp edge compared to a series 2 as its round / smooth the whole way around.
1. Take off the front lense of the new unit, just twist it.... turn over and remove the 2 screws from the back of the unit that hold the cluster in place , swap out the old back from the series 2 which has the green lights........
once the new unit is screwed back into the series 2 back plate replace the front ring and glass from you old series 2.....
There you have it! Also the high beam jewel comes out towards red when lit compared to series 2 which is a dull blue.
My car now runs with 1 mile accurate.........I have larger radial tires. 205/70/15.
Here is the etype part number if you find a complete speedo....
front face reads SN 6322/09
Now like ive said before, you can just plop in a mark2 3.8 overdrive unit.
Those part numbers are SN6317 08 OR SN6317 08A.
The 08a is a newer unit with bars between the trip numbers and more modern spring unit.
Remember though, they only read 140 miles per hour, with the high beam jewel on top......
Also the light behind the units are BLUE, But if you have no care they will work fine....
Remember YOU CANNOT USE THE SERIES 2 BACK COVER. Why? because the 3 jewels are on the bottom, the plug lights wouldnt match up, so you would have to live with the blue backround lights...
A mark 2 speedo you can get for 30 to 150 dollars..
The real etype is around the 400 dollars zone......
Well worth it for me..........
Hope this helps someone fishing at auto jumbles and swap meets..........
Good Luck
GTJOEY1314

The correct ratios for the speedometers that Jaguar (Smiths) used are actually on the faces of the speedo's themselves.

3.07:1
kph 700 = 20x35
mph 1120 = 32x35

3.31:1
kph 760 = 20x38
mph 1216 = 32x38

3.54:1
kph 820 = 20x41
mph 1321 = 32x41

Thus to make any of the speedometers for the E-type, 3.8l anyway, all you needed was a supply of faces, KPH/MPH and different model numbers and ratios, and different gears for the odometers, 20 tooth gears for KPH, 32 tooth for MPH, and another set of gears for the rear axle ratio. Pretty simple and optimal, not too many extra parts sitting in the warehouse for Smiths. Now, getting the needle to swing right, that takes someone who understands how the magnet and spring really work, which is not me.

I have a 3.07:1 speedometer that I was going to use in my car, but it is the KPH one .... I'm in Canada; SN 6322/10 700

Cheers, Mark R.

Thanks guys, but has someone already done the measurement thing and the rotations. Hopefully someone had done it and we can send out our gages without doing all the above..
Thanks again everyone.
GTJOEY1314

Nisonger in New York could also do it.

Re re-synchronising, Contact Morris, at West Valley Electronics in Reseda CA.

Re re-synchronising, Contact Morris, at West Valley Electronics in Reseda CA.

thanks for doing all the footwork Joseph. I too have a e-type that Dick Maury at Coventry West converted to a 3.07 from a 3.54, So while we may not be accurate on the actual mph we would have no problem driving in tandem somewhere at a set speed between us. I understand, but have not located same yet, that there is a company that will calibrate our speedos to the correct number of turns. If anyone knows who that is please post on here so Joseph and I can tell the cops that we really were doing 50 and not 60 whatever when stopped.

Bruce

Edited on 2013-05-26 11:26:56

Well, the good news, a overdrive mark 2 gauge works fine, the speed is correct, and there are a 2 versions for a newer look towards the etype.
Heres the catch, It only goes to 140 and the high beam jewel is on top of the gauge. All the wires reach, but it doesnt look right.
Next thought was to then switch the outside dial with the mark 2 guts, sounds simple enough, only problem the etype face plate has the miles in the wrong spot, because it has 20 miles more on the face.Get it.?
So now the old mechanicals with the new face would be 20 miles slower..........
Oh well worth the try....
ANYONE HAVE AN ETYPE 307 GAGE IM IN.....
Thanks GTJOEY1314

Thanks young man........
gtjoey1314

To be technically accurate, Jaguar switched the US market cars to 3.54 rear ratios in late 1963, way before the twin Strombergs. Other ratios were available but very rare to find a US delivery car with anything else.

Edited on 2013-05-25 6:45:11

In my opinion, the 307 is the best of all worlds. IMO.
Without a 5 speed, keeping the original etype feel.
The original 3;54 REAR was a joke, it was compensating for lower horse power and twin strombergs.
The 307 is the best of both worlds.
Taller gears or you setup was thought of but the down fall is you car is dead off the line all the ways to 45 miles per hour.
We tried them all, also taller gears do not have that punch around 90 mph.
Now going to a 5 speed and all that totally changes the story but I stayed with my bullet proof 4 speed all synchro.
Will report back, thanks for the info on the speedo, will see if all works out okay...
GTJOEY1314

How different is the city type driving in an E with the 3:07 instead of the 3:54 ? I do not have much opportunity for long distance cruising but have thought for awhile that up at 70-80 mph it is wound up higher than it needs to be. I have a car with a 2:53 and I love how it lopes along at highway speeds but it is a dog off the line.....but it does not have near the power or torque as an E-type. I have always been impressed how after about 30 mph my E does not care too much about being in 4th even if I want to punch it. Does the 3:07 just require more frequent gear shifts to keep the good acceleration ?

David Barnes
68 E-type FHC

Edited on 2013-05-24 20:08:56

The insides should swap without a problem. You may or may not have to swap the odometer reset shaft in order to interface with the cable, otherwise it's a drop in.

If you have some patience, it's not all that difficult to reset the odometer reading to match your original. I'm sure you're familiar with Anthony Rhode's e-book:

http://home.comcast.net/~rhodes/PDF/speedo.pdf