speedometer niose

[Dick M]

My speedo started to make a grinding type niose. It ebbs and flows when driving. I recently put in a new spedo cable. It appeared to have sufficent grease on the cable when I installed it. So I'm not sure if its the spedo or the cable. If it turns out to be the spedo making the noise, is there a proceedure to lube the spedo or does it need to be rebuilt??