Chevy Corvette Forum banner
1 - 3 of 3 Posts

·
Registered
Joined
·
9,843 Posts
Discussion Starter · #1 ·
When I installed a TH700R4 (aka 4L60) in my '71 is used a 90 degree speedometer cable adapter to extend my cable life. Without a 90 degree adapter the cable will eventually break at the sharp bend that is about 4" from the transmission:


I also made a 2-1/2" extension for the adapter because the governor housing was right in the way. Then I had to make a solid cable extension using a piece of 3/16" tubing and 1/8" square key stock with its ends filed down to .105". Then I made a new speedometer cable/housing that is about 8" to 10" longer than OEM so the cable/housing makes a larger gentle bend just ahead of my speedometer. It's tight bends and lack of lubrication that eventually destroys speedometer cables over time.
 

Attachments

·
Registered
Joined
·
9,843 Posts
Discussion Starter · #3 · (Edited)
I tried a 90 degree adapter when I installed my 4 speed. Could never get it to work right
What issues did you have? The 90 degree adapters come in three different styles; underdrive, overdrive, and 1:1. If you had problems you must have tried using a wrong style. The ones used for speedometers and tachometers will have a .104" square stem sticking out of it and that stem goes into the square hole of the nylon driven gear.
 
1 - 3 of 3 Posts
Top