350 hydramatic trans speedo gear

[kcwis]

How easy is it to replace speedo drive gear? Speedo works when ran w/cordless drill, Do the drive gears sometimes loosen up on the output shaft?  1976 GMC 1/2 2wd 350 eng. Removed adapter at trans,seems to be ok, hard to see gear on output shaft of trans.

[Henry]

Hi kcwis:
There is a difference between the speedo drive gear and the driven gear at the transmission. The drive gear is a big job to replace. The driven gear is easy. The driven gear should be right inside the adapter you have removed...you may need a pick or small needlenose pliers to fish it out. There should also be an o-ring in there with the driven gear. I have no knowledge or advisement on looseness of the gear set other than to look for unusual wear on the driven gear teeth or engagement slot for speedo cable.
Regards,
Henry