I used to have a 85 speedo in my car, and i put a 145 speedo in, would it effect the speed showing on the speedo. I think it might be 10 off in not for sure, and as soon as i go over 90 the needle starts bouncing real bad, does anybody know who to fix that problem

 

if all you changed was the speedo it shouldn't have any effect on the reading. the drive and driven gear at the trans tail housing give you the reading. you might want to greese the cable.

 

where should i grease it right on the connection that plugs into the cluster??????