gearheadz

Problem: my odometer is not advancing although the speedometer works fine.

I have my dash out so I decided to take a look. The number wheels work fine. When I rotate the tenths of a mile wheel (behind face) manually it advances the mile wheel appropriately and so on. So the counter mechanism seems to work fine. But as suspected when I spin the speedometer up to speed, it does not advance the tenth of a mile wheel at all. Therefore no odometer advancement.

There are replacement odometer gears available, is it something that simple? Also, how does the speedo needle come off? I suppose its a pressure fit that requires it to be pried off just like the other gauges but I don't want to break it. Any comments or advice will be appreciated.

Mark

gearheadz

TTT...c'mon guys!

Rockn-Roll

I'm really not sure how the odometer works. I've never heard of an odometer that doesn't work when the speedometer does work. I don't know of an easy fix other than removing the speedometer/odometer assembly and taking a look. I'm not sure how the needle is attached either...look real close at where the needle fits onto the pin. Look for cuts around the hole in the needle part which would indicate that it snaps onto the pin. If there are snaps there, then you will need a jewelers screwdriver set to gently pry the snap tabs away just a bit so you can slide the needle off without bending it.

SevenT1Shark

I know on my 71 that when i put the trip meter back to zero i have to pull the little **** straight down, only then will it start to register. Try that.

rickales

The speedo cable is magneticly coupled to the needle/pointer and bias spring. There are a couple of worm gear to couple the speedo cable to the number wheeles. I've owned three 68s and every on, the odometer has quit working around 85K. Problem is the worm teeth wears away so the drive gear on the cable no longer engages the 1st worm. I looked all around for replacement gear with no luck, it's probably a $2.00 part.

If you are very careful, you can get the odomerer apart without removing the speedo pointer/needle. Remove the screws on speedo face, then you can reach through the "BRIGHT" hole to reach the screws holding the back of the housing. Remove those screws and you can split the housing, the odometer stays with the housing back and the needle, housing front, and mag pickup stay with the speedo face.

If you find replacement gears, let me know as I'll have my dash out until spring.

daily_driver

the nestled bottom gear can be found for 10 bux (cheap black nylon replacement) at corvette central (odometer gear...)

gearheadz

Thanks to everyone for responding.

Rick (rickales), I was able to disassemble the speedo using the method you described but I can't figure out how to get to the 1st worm gear. The speedo shaft magnet/rotor is in the way & its appears the only way to remove it is to take the needle & face off. Any ideas?

Mark



[Modified by mdsmith, 8:46 PM 12/7/2001]

daily_driver

you need to undo the 2 1/4 inch screws in the cylindrical thingie...

youll need a barbie doll sized wrench for that!! :lol: :lol:

you can then separate the whole assembly far enough to have a bit of room to work with...

its a bit tricky, but very do-able!

gearheadz

Thanks d_d,

I'll give it a shot in the morning.

Mark