Speedometer Problem

I would check your cable - both inner core and outer casing.

 

check it for what? wear? deformation?

it was fine, then wasnt. just not sure what to look for.

 

Hopefully disconnecting the cable will make a difference. If the cable is mangled, it could possibly have the speedometer input in a bind.

 

I had the same problem last summer, except it would start grinding any time I went above 30-ish mph and wouldn't stop grinding until I was below 5mph. The speedometer end of the cable was destroyed; the last inch or so was rounded out and the tip was broken off in the speedometer, and the needle in the speedometer broken as well. I bought a used speedometer off of Ebay but never got around to getting it back in. You'll want to pull the speedometer out and inspect it closely for internal damage. If you're lucky, it'll just be the cable.

 

I pulled the cable from the back of the speedo and it looks fine/not mangled. The dial needle is still pegged over to wide open

 

I've seen that happen when grease or crud gets between the aluminum cup and the rest of the spinning bits.

 

Mostly any fraying, rough places, or kinks that can catch-and-release creating a sort of slingshot effect at the head.

 

Okay. The cable has killed 2 speedo clusters now. No kinks or frays or binding on both ends.

 

If the inner core is a mite too long, it may bind when the outer casing nut is tightened at the top end. Shenanigans can result.