Gkn to btr speedo

[mcosh]

Guys before I take my dash out and get my speedo recalibrated I wanted to check there's not an easier way. I upgraded to a btr dif recently and we have mounted the old gkn flange on propshaft with sensor as we couldnt get it to work off the btr mount. Speedo ok upto 40 but then heads out showing 95 at 80 etc. My speedo wouldnt read from the btr position and I wondered if there is a different sender?

[jeboa]

I'm not sure if there is an easy way? There may also be a 'box' in between the speedo sensor and the ECU, although I think this shouldn't be a problem if you're reading correctly at about 40mph.

I've got fed up trying to get my old GKN mounted sensor reading correctly. I was about to invest in one of these:

http://www.autometer.com/universal-gps-speedometer...

But thought I might try making my own.... one day.... I've got the parts, just not the time....

[mcosh]

Don't think that will work with my existing speedo will it???

[Ozstyle]

Hi,
here are electronic devices out there that deal with this issue, I've seen them on the web. They proportionally adjust the speed signal pulses from the sender to the speedo, eliminates the need to recalibrate the speedo. Jaycar rings a bell.
Senders are different based on the instrument (ETB or CAI). There was a cross over period where both instrument types where used with the GKN diff which may play a part. Sender type is selected on trigger wheel design. That's why the BTR sender seams to require a much smaller air gap than the sender fitted to the GKN.

Ozstyle

[griffdude]

Ant had this issue when he rebuilt his Griff that now belongs to DocToad, might be worth an ask?

[jeboa]

I think I have one of those changeover cars - never managed to get the speedo to work properly after the instruments were refurbished.

However, on the plus side - it reads about 70 when I'm doing 110 - so less complaints from the passenger seat....

I know how fast I'm really going based on the gear I'm in and the rev counter.