Recalibrate electric speedo 700R4

[Roger Bentley]

Just changed rear gears from 3.08 to 3.73. I have a 700r4 trans with electric speedo in my 1990 GMC Sierra. My speedo is now way off. How do you re-calibrate? This has a magnetic sensor rather then the gears like the earlier 700R4"s. Any help would be greatly appreciated.

 

[PlayingWithTBI]

How do you re-calibrate?

Here's a link to a site. IIRC @someotherguy posted one too.

How-To: 88-91 speedometer calibration 25085515 91' tach upgrade - The 1947 - Present Chevrolet & GMC Truck Message Board Network

How-To: 88-91 speedometer calibration 25085515 91' tach upgrade The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board

67-72chevytrucks.com

 

[revmatcher]

Just changed rear gears from 3.08 to 3.73. I have a 700r4 trans with electric speedo in my 1990 GMC Sierra. My speedo is now way off. How do you re-calibrate? This has a magnetic sensor rather then the gears like the earlier 700R4"s. Any help would be greatly appreciated.

Any chance you want to sell those 3.08s?

 

[someotherguy]

Here's a link to a site. IIRC @someotherguy posted one too.

How-To: 88-91 speedometer calibration 25085515 91' tach upgrade - The 1947 - Present Chevrolet & GMC Truck Message Board Network

How-To: 88-91 speedometer calibration 25085515 91' tach upgrade The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board

67-72chevytrucks.com

Sticky'd in the electrical section: https://www.gmt400.com/threads/recalibrating-1988-1991-speedometer-dash-cluster.62022/

Richard