67 Odometer Repair

[Ron N.]

Thanks, Ron

[John H.]

Re: 67 Odometer Repair

Thanks, Ron

Ron -

I don't know enough about the nuances of the various types of replacement second and third worm gears to be comfortable with that (common/chronic) failure and repair, so I sent mine out to those who do.

[Lynn H.]

Re: 67 Odometer Repair

Thanks, Ron

Ron,
I have never seen any articles on this, but have recently had the opportunity to get up to speed on the repair of speedos and tachs. I ran into a defunct speedometer operation, and have been sorting through parts for about a month (with many months to go) to get anything I can find that is Corvette related. As John mentioned, the common failures that occur are usually very similar. I have found that working on these items is not as complicated as I and most others have come to believe. They are actually fairly simple to work on, once you have an understanding of what is in there and how they operate. I believe the biggest problem for the average restorer is the availability of parts to make repairs, once your malfunction has been diagnosed. I am sure some pieces may still be available, but also think that many are not. I have created a spread sheet to assist in sorting through the mountains of speedometer parts I am looking through. ALL the components for every tachometer and speedometer from 61-82, do not fill one page. Many of the parts were used for many years, and also went into instruments for a variety of vehicles as well. Some may still be available, but I am not certain about current availability. All the NOS parts I have found come from AC Delco, and they had (have) a specialized catalog for Speedometers, Tachometers, Gauges & Service Parts.
One of the things I have found is that on the older Corvettes the numbers appear to be silk screened on the individual dials and can come off very easily with handling. I would suggest being very careful with the the number "clusters" if you decide to attempt this repair yourself. MANY speedo issues, can be dealt with disassembling, cleaning, and reassembly. Others require replacement of parts and if yours has been frozen for some time it may have stripped one of the worms John mentioned. If you have a donor for parts you may be able to tackle this yourself, but I would suggest working on the donor first to get an understanding of how they are put together. If you have any questions I can help you with send me PM and I will do what I can.
Lynn

[Donald O.]

Re: 67 Odometer Repair

Thanks, Ron

Ron,
Best expert I know is our own Joe Ray.
DonO

[Jack P.]

Re: 67 Odometer Repair

My odometer & trip odometer stopped working long ago and I now want to get it fixed. Speedometer works fine. I’m guessing it’s the internal gears. Can anyone help me understand the possible causes and difficulty of repair? Also are there any old Restorer issues that provide DIY repair instruction or should it be sent out to an expert?

Thanks, Ron

I tried repairing my trip and odometer and found that you need to replace all the gears and number wheels. Almost all broke after 40k to 60k miles. The trip wheel and gears place a lot of pressure on the odometer gear leading to failure. I found it best to send out and have all parts (wheels and gears replaced and calibrated) it cost about $110 to $150 from most repair shops. Many are listed in Driveline mag. Each number wheel costs about $50 each and then the cost of gears if you do it yourself. It is cost effective to send out.

The problem is taking out the cluster to get at the speedometer.

Jack

[Ron N.]

Re: 67 Odometer Repair

Thanks to all for the replies. Based on your input I decided to send it out. I'll check with Joe Ray and others in Driveline. Hopefully I can find one locally.

Ron