My speedometer doesn’t return to zero, it only goes back to 25 mph. Is there a way to adjust this?

It is not an adjustmen, The speedo works are probably gummes up. I found the best is to remover the speedo and have it cleaned and lubricated professionaly.

Thanks Chev Nut, I’ll start looking for a speedometer shop.

The needle on my 55 went to the right out of sight. Is there a way to get it back without tearing it apart? Worked fine before.

I am guessing you have the same issue as above and the solution would be the same. I did have a speedometer shop tell me that removing the speedometer and turning upside down and then lubricating with WD-40 and letting it sit a couple of days MAY soften the grease but with all that's involved to remove I think it is best to have it professionally repaired.

I agree with all the replies so far. I used to fix speedometers years ago, and the symptoms point to a sticky meter movement. The forces involved with the meter movement are quite small, so it is very important that the meter movement pivot points be cleaned and very lightly lubricated, and the hair spring(s) be not tangled or sticky.
After all this time, the magnet may have lost some of its magnetism. A professional can re-magnetize it to the correct strength and calibrate the speedometer.

Do you think turning the Speedometer Cable backwards at the Transmission will let the Needle return to Zero?

Yes, but it won't solve the problem.

Probably not. If the needle is stuck due to hardened grease and dirt the magnetic field will probably not move it.

I'll try it today and see what happens.

Well, I tried it and no sign of the Needle. I just don't understand where the Needle went. I don't want to pull the Instrument Cluster out as in disconnects all the lights and everything and is a pain in the A--. So I may have to drive it a while without the Speedometer, don't know what else to do.

Ok. Here are a couple of crazy ideas to consider.

Did perhaps the needle fall off of the armature and is hiding?

I’m not sure what access you might have to the back of the instrument cluster. If I remember correctly there is some type a an access panel on the firewall. If you can get some access take a can of pressurized air that is used to clean computers. Shot short blasts into the speedometer area and see if that makes the needle move to a visible location.

My old Garmin GPS has a very accurate speed display, so I use that when I drive a vehicle with an unreliable speedometer.
Yes, the 6 volt cigarette lighter receptacle will take a USB adapter to power it. In case you are worried about it not being 12 volts, USB only uses 5 volts, so no problem. I have done multi-day trips using the USB adapter to power devices, and everything worked great!

Maybe I'm just 'lucky' but my Garmin won't work on 6v. I tried it and it would work for a few minutes then revert to battery. I ended up having to put a 12v step-up in the car for it to work right.