I have an '86 F-150 302 4X4, it has a Borg Warner 1345 Transfer Case. The problem I have is the speedometer cable won't engage the gear inside of the transfer case... Its a brand new cable and gear on the end. I can reach my finger in the transfer case and that gear spins but it feels like the gear inside is worn. How do I gain access to that gear, and is it replaceable?