Fix 700R4 Transmission Speedo Sensor Leak - IROC-Z Barn Find EP81

This video shows how to remove the speedometer adapter and replace the seals in the speedometer cable adapter. One of the places that a 700R4 can leak transmission fluid is where the speedometer cable connects to the drive gear at the transmission adapter. This design is similar in other GM transmissions of the era before electronic sensors were introduced.

As I was putting the car away for the winter I noticed a slight leak (a few drops on the garage floor) from the 700R4 automatic transmission. As the car sat over months, the leak became much larger, probably at least a pint. I went into this video thinking I likely had an extension housing seal leak, but it seems to be centered on the speedometer cable adapter seal.

Background: This is a "Barn find" 1985 IROC-Z Z28 Camaro with Tuned Port (TPI) LB9 engine that had been parked in the same spot without running for 25 years. The original owner passed away and his father sold the car to me. It had just over 101,000 miles with virtually no rust on the body, very unusual for spending its life in Michigan. This series starts at the beginning and runs through what it has taken to make this car run again.  It will continue as I work through continuing to make the car road worthy and bring it back to its former glory.
 
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