Slick 60's

always had a little noise to it, but today it got real loud and the needle was going between 50 mph and 6:00 at 70mph.
even thought once or twice it might pass 0 and go around again.

not sure if theres anything that can be done other than replacement of the complete unit

If you don't have a spare, LMK.But as you know, it may be the cable affecting it.

Paul

Paul
i do have another one and the end of the cable is good.
i used to have a tube of special cable grease, not sure if i still have that or not.

If the cable gets dry or starts to un-strand, it will make that speedo dance, and sound like a Poppin' Johnny with a miss on number one!
I used to pull the cable out, stick it in some trans fluid, and quickly snatch the cable back into the housing.
Paul

Erratic speedo movement is usually caused by the cable binding and releasing. Take the cable out and try to lube or replace.

Years ago I rebuilt Speedometers and GM transducers (the mechanical cruise control units) in my shop. The repair is very simple for your speedo problem. There is a drum in the speedometer it hooks to the needle. That drum has a set of magnets that spin inside the drum on GM usually the bushings would wear and allow the magnets to touch the drum making the needle to bounce or sometimes make a full 360. Ford had very few problems with bushing wear but would get gummed up I think from what the factory lubed them with. I have always used CRC LECTRA-MOTIVE ELECTRIC PARTS CLEANER to clean the drum out and then lube with a light oil like 3in1. Remove the odometer by pulling the single horse shoe shaped clip you may need to loosen the face plate to get the odometer out. A new speedo you can wash down with no worry but the aged units tend to wash the numbers off the odometer when cleaning. Once you are done you can test using a variable speed drill I have a crimp on speedometer cable end in my tool box I chuck up in the drill. Napa has that end for 2 bucks Balkamp # 615-1823.

So just to make sure I explained this correctly in the Ford speedometer the the magnets that spin inside the drum get gummed up and grab hold of the drum when it first starts to occur it is usually in colder temperatures. So cleaning out the drum and magnets fixes the problem. Also oil it from where the cable attaches to the unit. The cable should be cleaned and lubed while your there. I used to use white lithium grease but changed to dry graphite because the white grease gets worked into the speedo head that can cause problems years down the road.

thanks for the tech.

it first started making noise when i lived in Alaska, nowhere much colder to test mechanical stuff.

im going to take it apart as soon as i have some extra time and will post the results here then.