Speedometer Went Crazy
 

Good evening. My speedometer was showing about 10 miles over the speed I was doing. Then it went to 15 miles an hour and I was going 75. I am new to the classic world of the C3 (got last Saturday). Does it have a cable to the wheel? Spring?

Any helpful hints will be appreciated.

Haynes book is on the way too.

David

It has a cable that goes from the speedo to your transmission.

Disconnect the cable housing from the transmission. The inner drive cable should be square on the end so that it fits into the small gear inside the transmission. Sometimes the square end will become "rounded" from wear causing the speedometer to read incorrectly, The "inside" of the gear in the transmission should also be square-shaped...if it is rounded, the gear itself is worn out and needs to be replaced.

Also, once you remove the cable housing from the transmission you should be able to turn/rotate the inner cable with your fingertips or by using a pair of needle-nose pliers. Examine the outside of the cable housing where it is secured to the car body to make sure it is not smashed or melted from exhaust pipe heat.

The above things are the easiest problems to look for.

first get a watch and a hunk of interstate with mile markers. it is a corvette. it may have been correct!

Also, save yourself some grief and get the GM published/licensed shop manual and assembly manual specific to your year. Not to knock Haines, but they are far better resources. RockAuto has them, and all of the Corvette vendors.

Everyone has a stinken smart phone nowadays. Get an app and get your speed from the app. I use it all the time. Way more accurate than mile markers.

Does your car have cruise control? If so it could be the transducer also. But the above comments are good places to start.

I am having trouble removing the cable from the transmission, is there a trick to it????

It also seems loose but it wont turn to loosen.

Also, I now know where the trans fluid is coming from too - right there LOL