oscillating speedometer, brake hub problem

[Willy Briones <Wilfredo.Briones@Ebay.Sun.COM>]

any ideas please -

1.   as soon as I hit 60 mph - the needle on my speedometer gauge 
        starts to move across the dial on a span of 10-20 mph -- 
        replaced the cable, tried another speedometer - but still 
        the same problem - hate to take down the tranny just for
        this but also hate not knowing what my speed is especially
        past 65
        
2.   replaced the rear drum brakes on a '60 BugEye with drum brake
        assembly from a '74 Spridget using the same '60 axle - found 
        that the they do not fit right - the hub rubs against the 
        brake piston rubber seals - had to cut an old bearing 
        and put a spacer (about 1/8" thick) before the bearing - 
        has anyone experienced this?
        
Willy -