I can’t figure out how to fix this, it’s very annoying since I don’t know how fast I’m going since it’ll swing from like 40-60. Anyone have any help

 

do you have cruise control unit on your car? 82s and 83s still used old 1960s style cruise control driven by speedo cable,can cause speedo issues if bushings in the cruise control unit get dry and bind.

 

Your speedo cable is dry and needs to be cleaned and lubed

 

it has cruise but it’s unhooked, I guess I’ll need a diagram to see exactly what you mean I can’t really picture it

 

is there a diagram or video or something to show me how to do that? Stuff like that isn’t intuitive for me

 

Look under the hood. It's a goofy looking box with two speedometer cables going into it and a couple wires. If the cable goes right from the transmission to the dash, then it's not connected to a transducer. At that point, you can try cleaning and lubricating the cable, or replacing it with a 1 piece cable. But it might also be the speedometer itself that's gone bad. BTDT. The other possibility is the speedometer gears/sleeve in the tailshaft of the transmission might have eaten themselves. Just gotta work thru it.

 

The cruise regulator is the object that the blue & green wires are plugged into. It's on the left strut tower near the AC compressor. If you have that, note that there are 2 cables going into the rear of it... one comes up from the rear of the transmission, and one goes to the dash.



The way those regulators fail is, there's a spinning copper disc inside, that acts like a generator, and when the cruise is set, a spring is tensioned corresponding to the speed, which the current produced by the generator balances against. Then if the speed is too slow (spring wins) a vacuum port is opened that feeds vacuum to the diaphragm that opens the throttle; and if the speed is too high (generator wins) the port closes, letting the throttle close. The bearings for the copper disc system wear out and let the 2 halves of it rub against each other, creating LOTS of friction, which tends to try to stop the cable from turning; the cable binds up, and instead of turning smoothly, the lower one, from the trans, gets torqued up real tight (dash instrument goes toward zero), then lets go in a sudden burst at high speed (dash instrument flings toward infinity).

You can try lubing the cables but if the regulator is toast, the only cure is a new regulator. Good luck with that. I've been fighting it for over 30 years in my car.

 

I believe A1 Cardone rebuilds above Transducers. Or they used to.