Speedometer Cable is fine, gear in t- case?
 

1986 toyota pickup, base model, 22 R. Alright, got the speedometer cable out of the t- case and i spun it with my helper in the cab, it works and the speedo went up when i turn the cable. pluged it back in and it doesnt move the needle. is there a gear inside the t- case that can wear out? if so, where can i find a replacement gear, and is it difficult to replace? Thanks!