MG T-ABC

Cap, operating shaft (Moss 43 443-020).
Should the Cap be tightened or left a little loose? If I tighten it locks the operating shaft.
Maybe tighten with an appropriate shim washer?
Thanks.

The required washer was missing from the last mechanic in there who left the cap loose.
Sorry about the bandwidth and energy consumed before I got my brain and car in gear.

Definitely tight!