I replaced my motorguide hand control that served me well for the last 11 years with a new Vari-Max and mount. The new one has the larger size shaft. When I turn the TM in the mount the thing squeels like a scalded ape. I have adjusted the tension on the knobs from tight to loose and it doesn't seem to help. I thought about some lube but I think that would just collect dust/dirt and make it worse. Any ideas other than smart a$$ comments to replace it with a Minn kota.

Is the shaft rubbing on anything below the mount? If the mount is the correct one for the shaft size it shouldn't be that the mount is the culprit.
It's just me but, I could handle a little dust caused lubrication if the lube solves the problem. The boats going to get dirty anyway.

get some powdered graphite and use it. work it good while dry and get some of it the embed in the shaft.

I'll give that a try. Thanks