87 suburban speedo problem, any suggestions?

[Nodnarb76]

My 87 suburban 2wd with Th400's speedometer hasn't worked since I got it.
I have replaced the cable(s) and driven gear already. Once I replaced the driven gear, it worked for about 7 miles then stopped. Every once in a while when the truck is cold (first startup of the day), the speedometer works for a mile or so then stops.

When the driven gear was replaced I had my friend at work do it ( work at a dealership) and I didn't ask him to check the drive gear inside the transmission.

I seem to have some sort of adapter between the cable and gear housing (see pics), anyone know about it and if it would be likely to fail?
Posted via Mobile Device