Hi all,

Last time I had the car out, the speedometer just quit working. I got under the car tonight hoping to find the cable came off... But it's connected. When I rebuilt the motor and transmission last year, I installed one of those 90 degree connectors to make it a little simpler. And it worked fine until it stopped working. So I know it did work.

When I checked it tonight, the connectors felt solid, they didn't wiggle. However, there was some relative movement in the area where the red arrow is pointing. It wasn't a lot, but a little. Is that normal?


If that's not the problem, where do I look next? I'm deathly afraid of getting into or behind the dash... I'm sure some plastic part will break on me!

Suggestions?

 

totally unclear why you added the 90 degree connector. however, remove cable from connector. twist inner cable. is it broken? spin inner cable with a electric drill. I forget which way but I think its counter clock wise. try it both ways. does the speedo move? if yes pull your 90 degree connector and check it. if no, unhook cable from back of speedo and pull inner cable out. is it broken?

 

Try the drill method to eliminate the gauge area (fingers crossed for you, Mpls Funk). If just the cable is broken that's not too terribly difficult to disconnect from the gauge but still no fun. The only other failure point is the smalldrive gear in the transmission. As I recall, that should be easy to check by merely removing that securing bolt.

You are not wrong in fearing the brittle plastic! A few months ago, the long arm of my tachometer needle fell off. Yes, fell off – I could see it lying at the bottom of the gauge. Damn. Even trying my best to be gentle, I broke a mounting tab that holds the gauge to the dash... that damn huge and heavy wiring harness was a bear to get positioned over the speedo/tach housings again.

 

I thought it would make connecting the cable much easier since now I don't have to negotiate a 90 degree turn in the cable right before it connects to the transmission?

Thanks for the tip... I will remove cable and try!

 

I too have recently been down the same slippery speedo/tach slope. Maybe you will be lucky and it’s the 90 degree coupling. My story is extremely painful, after the first the tranny gear went out, I had it replaced (they are plastic on the manual cars). I live a bout 20 miles from the Corvette Service Shop, and as you may guess, by the time I arrived home my speedo was dead. Took it back and the Service Manager said the only fix was to pull the tranny, (plastic gear was stripped) and have it rebuilt. So that lead to a new clutch and flywheel. This time the speedo/tach worked for a few months! I decided to bit the Bull and pull the speedo/tach out, so they could be rebuilt. I also replaced both cables, and purchased new 90 degree couplings. Trying to push the drivers side dash back into place (with a 48 year old wiring harness) was near impossible. I was hesitant to remove the steering column thinking it was beyond my expertise. Anyway after putting everything back together the speedo still didn’t work. I took it back to the repair shop and they replaced the plastic gear, the Service Manager said that on these old transmissions, there is a lot of play which causes the plastic gear to get stripped. The verdict is out so we will see how long the new gear lasts. Good Luck, do the easy test with the reversed drill first.

 

I got under the car tonight and tried the cable in the drill test and the speedometer worked! So the cable and the meter are OK. However....

When I took the cable out of the connector, it looked like small metal flecks on the end of it, which probably isn't good?

There looked like there was plenty of Grease in it. Here is a picture of the fitting/connector. There isn't anything jumping out at me in this picture?


So then I thought I would try to take that connector off and connect the cable direct to the trans like original. But I can't get that darn connector off! There is almost no room up there to get a wrench on the flats. I was able to get a channel locks on it, but couldn't get it to move...

Any suggestions?

 

You have the same problem that I did trying to remove the 90 degree adapter. I am thinking the service shop I used employed a special wrench or they took off/loosened the bracket on the tranny. I have a manual 73 Muncie and your bolt holding in he plastic gear looks differ than mine, it may be the head on yours is larger. Have you tried “Long Nose” Vice Grips. Hopefully someone will tell us how the adapter is removed. The service shop that I use typically installs the 90 degree adapter. They are owned by one of the largest used Corvette Dealers in the country. I know some folks don’t like the adapters.

 

That's good news about the cable and gauge. The metal on the end may just be the loose strands of the cable winding and if so isn't anything of concern. You can flush clip, grind, or file them if you feel they're interfering with inserting the end into the housing.

 

That cable looks like the end broke off if I'm looking at the pictures correctly . wipe some of the grease off , those cables always twist off the end ..... My speedo just quit in my 1980 , the lower cable from trans to cruise control transducer broke ... turns out the original cable didn't like 140 mph

Edit to add .... My original cable had a 90 degree reinforcement right where it goes into the transmission that I transfer over to the new cable