700r speedo cable

[ToonMan]

My 67 Chevy pickup has a 700r4 transmission in it. The day I test drove it the speedometer was not working. When I went to purchase the truck the speedometer was working. And then I took it for a drive last week and the speedometer was not working again. I contacted the previous owner and asked him what he had done. He had said that the cable had slipped out. I checked it and it was in and fine. So anybody have a suggestion on what I should look at next? Thank you

[Accelo]

A lot to cover here but I will hit a couple of basics. This relates to the 700R4 made till 1992.
If it was working and isn't the most common issue is the square hole in the plastic gear rounds out. So the gear turns but the cable doesn't.
The gear can be spinning on the transmission output shaft, or the plastic teeth missing.
If the cable is new the internal cable can be too short. Typically this strips the end of the plastic gear because it doesn't have enough engagement.
If you are older, like I am, magnification may be necessary to see the issue.

[ToonMan]

Originally Posted by Accelo

A lot to cover here but I will hit a couple of basics. This relates to the 700R4 made till 1992.
If it was working and isn't the most common issue is the square hole in the plastic gear rounds out. So the gear turns but the cable doesn't.
The gear can be spinning on the transmission output shaft, or the plastic teeth missing.
If the cable is new the internal cable can be too short. Typically this strips the end of the plastic gear because it doesn't have enough engagement.
If you are older, like I am, magnification may be necessary to see the issue.

Excellent. Thank you. I will look again. Ya magnification will be needed. Lol.