Page 1 of 1

The CORRECT way to Calibrate your speedo

Posted: 20 Jun 2023 10:05
by ra_01
Hi

This is a post from Australian Patrol website. Have anyone managed to use this method to correct the speedo. Since changing my tires to 33inch and diff conversion to 4.1, my speedo is out by approximately 10%.
To correct it, apparently we can either this method or an electronic device (this is more flexible i.e. you can adjust the setting when ever you change your tires). I have also attached the document with correct part number based on Diff ratio vs tire size.

I did call Nissan Midrand and it takes 21 days to procure the part on back order.

https://www.patrol4x4.com/threads/the-c ... eedo.7001/

Re: The CORRECT way to Calibrate your speedo

Posted: 20 Jun 2023 20:36
by mvcoller
Reef Industrial (RIMI) also does it.

There is a adjustment pod on the instrument cluster that adjusts the speedo. There is also one for the rev counter. Adjusting is done with a 4mm flat electrical screwdriver.

It took them 2 minutes to correct my revcounter on my GU Patrol some 10 years ago

I removed the cluster, took it to them and within 90 minutes the unit was back in the car and reading 100% correctly.

http://speedometers.co.za
They are in the Southern Suburbs of Jhb.

Re: The CORRECT way to Calibrate your speedo

Posted: 21 Jun 2023 07:49
by ra_01
Hi Malcolm, does the adjustment comes standard with the Patrols?

Re: The CORRECT way to Calibrate your speedo

Posted: 22 Jun 2023 20:01
by mvcoller
As far as I know it came standard on all Alfa Romeo speedos of the 1960s, 70s and 80s. I had 27 Alfas, ranging from 1967 to 1992 year models and we often corrected our speedos adjusting these pods.

It was also standard on the speedo cluster of my 1985 TB42 GQ Patrol. I was under the impression that it was a standard feature on cars of that era. I am not sure if modern electronic units have the feature.

Phone Reef Industrial and ask them if the speedo on your model vehicle can be adjusted to correct the over ir under readings you have.on your speedo.