Speedo sensor- five speed vs six speed

[BigDogRick]

Just finished installing my new transmission sensor (Evo style) on the total rewire of my Vintage Classic which has a six speed Baker upgrade. I found plenty to choose from. At least two stated clearly “ if installing on a six speed, this sensor requires the spacer that comes with the transmission”. So I thought the best gamble for a successful plug and play would be the Dakota Digital sensor. When I removed the old sensor the spacer was maybe 3mm, plastic, dried out and brittle. It broke up so I installed without it. Now it works but reads about exactly double my actual speed. I am assuming it is too close to the teeth. I am thinking I can fab a gasket of several different thicknesses and trial & error it. Any ideas?


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[Brandon Downey]

Sensors like this typically read via a magnetic field the rate at which those teeth go by (or the rate at which the teeth disrupt the magnetic field depending on the application). Unless these ones work a different way, I wouldn't think a distance of 3mm would double your speed. Probably more of a clearance issue requiring the spacer. I would first try replacing the spacer and see if that does the trick. Surely that won't be too expensive. If that doesn't correct it, hopefully someone with experience with these trannys will jump in.

 

[BigDogRick]

Sensors like this typically read via a magnetic field the rate at which those teeth go by (or the rate at which the teeth disrupt the magnetic field depending on the application). Unless these ones work a different way, I wouldn't think a distance of 3mm would double your speed. Probably more of a clearance issue requiring the spacer. I would first try replacing the spacer and see if that does the trick. Surely that won't be too expensive. If that doesn't correct it, hopefully someone with experience with these trannys will jump in.

Agreed. I did actually get a response from Thunderheart regarding the OEM sensor - but that is for the five speed - they still sell it. When I swapped this one out, it is clear it was spliced in as a replacement at the time of my six speed upgrade in 2005.

 

[Brandon Downey]

That's cool that Thunderheart got back with you. Keep us posted on the repair, very interested to see what fixes your problem.

 

[BigDogRick]

Just finished a lengthy email exchange with Keith at Thunderheart (they go by Thunder Max now). There is a programmable sensor for six speed Evo style V-Twins that should fit my bike. Here is the one they recommend.
https://www.thunder-heart.com/shopexd.asp?id=294&bc=no

Good for 95 to 03 bikes Harley type V twins. It must be matched up with the VDO stock speedo

 

[BigDogRick]

OK. Got the new Thunder-Heart adjustable tranny sensor installed and, after the maximum negative adjustment, I am still way off ... albeit not as far as where I started. I was at actual speed: 35 mph reading 90. After calling the adjustment to a -40%, I did so but still read actual speed: 30 reading 48. So I tried again as that indicated a desired adjustment well beyond the 10% still available (max +/- 50%). I did the full -50% and now I am actual speed: 35 reading 48. I have a hunch the Dakota Digital has a six speed vs five speed setting.

 

[BigDogRick]

This is painful to confess: I just did a a "adjust VDO speedometer" google search and lo and behold ... the stock Dakota Digital speedo has a simple-as-you-can-get calibration procedure built right in. Having a gps to tell you your speed and exact distance traveled is all you need. After going to this site http://www.gomog.com/allmorgan/VDOCALIBRATION.html , I simply followed the Aotocalibration option, told it when I had gone exactly a mile and the speedo did a sweep while was moving and set the new calibration and I matched within +/- 1 mph with my speedo to my speedometer app on my phone. I sure am glad I found this out now that I have been calculating my speed in my head for 18 years on this bike. What a hoot!

 

[Mr. Wright]

OK. Got the new Thunder-Heart adjustable tranny sensor installed and, after the maximum negative adjustment, I am still way off ... albeit not as far as where I started. I was at actual speed: 35 mph reading 90. After calling the adjustment to a -40%, I did so but still read actual speed: 30 reading 48. So I tried again as that indicated a desired adjustment well beyond the 10% still available (max +/- 50%). I did the full -50% and now I am actual speed: 35 reading 48. I have a hunch the Dakota Digital has a six speed vs five speed setting.

You get the LEDs in yet?

 

[BigDogRick]

Not yet. Its been kinda crazy for about four weeks straight. I have Celeste back from Cabo this week, settling in. That is all I have left on the bike. Still don't have a garage and I disdain doing that on a gravel drive in the AZ sun. Maybe I will ask Scot if he would mind me hanging out in his shop for a couple hours with a solder gun.