So my 1982 bird still has the original TH200C but a swapped 350 sbc, and since i bought it the speedometer gear was shredded, so I put a new one in, and it shredded again. I just checked yesterday and realized that the drive gear inside of the transmission is actually metal while the driven gears are only made out of plastic, I don't know if the metal gear was factory but it'd be a bitch to replace because the tail doesn't come off the TH200C. The gear shredding could be my error, I may have put the gear in wrong but has anyone had this problem and is there any other solution besides dropping the transmission and taking it all apart just to put a drive gear in?

 

Most likely, either the cable (or one of them at least, depending on whether you have cruise), the cruise regulator, or the speedo, is stuck and binding. My bet would be on the cruise regulator.

Probably nothing wrong with the drive gear.

 

I wasn't sure because I spun the cable and the speedo moved, but when I put it in the tranny it worked for a few minutes then stopped, so when got home i took it out and the gear was shredded, I assumed it was just because of the plastic vs metal teeth, I have an extra cable so i could try that but im down to one driven gear and i dont wanna ruin it