My speedometer quit working a while ago so decided to get it fixed. I sent the unit to classic instruments to have them check it out and they serviced the unit for me at no charge (thanks guys). I went to install it and it still didn't work. After fiddlin around checking the electrical connections (electronic head), checking for continuity, etc. I took the bullet connector back out to hook up a drill to the shaft to test the speedo head. Something didn't look right and I realized the plastic drive (driven?) gear was missing. Since the speedo worked previously I'm thinking it self disentegrated? I don't remember it falling out or taking it out of the trans. Is this normal? The other problem is how can I tell which drive gear is installed in the transmission without pulling the tail piece, as there are different diam. and gear teeth numbers. I'll need to know this when ordering a new plastic speedo gear. I'll also be draining the gear oil to check for bits of disintegrated plastic.
I picked up a clear plastic gear today at the transmission shop, will see if that works. GL-4 is conventional, correct? I usually get Valvoline gear oil, I think it's 90-140w. Same lube I run in my 9" diff.
The Jalopy Journal
