Author Topic: Speedo Question - 1987 GMC R2500 700R4  (Read 1002 times)

Offline COLT448

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Speedo Question - 1987 GMC R2500 700R4
« on: June 12, 2022, 03:36:56 PM »
Hi All,

This is my first post. Thank you in advance for your input.

I purchased a 1987 GMC 2500 and the Speedometer didnt work. Took a look under the truck and noticed that the 700R4 Auto Transmission has an electronic speedo sensor but the truck still has the mechanical cable running to the dash. That being said I dont have access to the old the transmission to change out the tail on the tranny. So my question is which way should I go? Electronic or Mechanical. looking mostly at cost?

1. Going Electric - I think i would have to purchase a new speedo sensor wire which runs about $15+. But im not sure if the existing speedometer in the dash would receive the new speedo wire and operate properly?
2. Going Mechanical - I would have to purchase one of those tranny conversion kits for $115+, open up the tail and change out the gear as well as the receiving connection.

Any input would be greatly appreciated

thanks