My speedo broke awhile back, it was the pin at the end of the cable, i replaced it and repleaced both bearings on the drive shaft, greased everything put it back together and worked fine. Went out this past weekend and it wasn't working again. Could I have put the wrong grease in I don't know if it was cold temp or not, would that do it or do I have other issues.

There is most likely ice either in your cable or in the end of driveshaft by the speedo hookup. replace the key and get a cable oiler. its a metal and rubber clamp that goes on the end of the cable and pushes lube down the cable when you spray grease or wd40 into it. also make sure you grease the lower driveshaft bearing regualry.

I also had a speedometer gear adapter that quit working, you should be able to rule out the cable by taking it off the adapter and turning it by hand... if it turns freely and you can see the speedometer jump, check the adapter/gear.

I would say you got some water down in there and it froze up,,, easy way to take out that little key. Make sure you have it packed with grease and you could possibly look into something to seal it up even better,,, not sure if silicone would stick or now but there has to be something. my vmax was like that,,, didnt matter how much grease I had in it, it popped them about every other ride. I got real good at swapping that one out and I was buying the keys 5 or 6 at a time.