Sunday, November 29, 2009

Odometer Repair

As soon as I drove away from buying the car, I realized that the speedometer worked, but the odometer and trip odometer didn't.  Since there's only one cable into the gauge and the speedo worked, I knew the odometer problem was inside the gauge itself.

Going by an article on the Pelican Parts web site, I knew I needed to get inside and check for a slipping gear on the main shaft.  The trickiest part is getting the gauge open.  It was clearly never meant to be opened because the metal ring around the gauge is bent around from the front to the back, holding everything in.  You have to carefully bend the back of the ring away from the housing.  A small screwdriver and a lot of patience is required. Go a little more than halfway around the gauge, prying the metal ring about 1mm, then go back and do more passes until the ring comes away.

Now that you have the front open,  remove two small screws on the back and gently remove the mechanism.

There are two parts to the mechanism - the gearing at the back and the mileage wheels at the front.  Don't mess with the wheels or the speedo needle if you don't have to - the wheels are a bear to put back together and you'll have to recalibrate the speedo if the needle moves on the shaft.

I played with the gearing mechanism a bit by hand and realized it was going to take a long time to get the dials to spin.  Then I realized that the trip odometer reset cable actually fits perfectly into the main speedometer cable jack.  I looked over at my drill and figured it could spin the cable faster than I could by hand, so I hooked it up and pulled the trigger.  Looks like my drill tops out about 110 mph!  I then saw that both odometer dials spun properly!  Argh!  I don't know what I did, other than making sure the gearing was all seated properly and turned things by hand.  It will suck if I put it back together and the odometer doesn't work again.  Since I'm diving into major demolition, I'll put the completion of this little project on the back burner.