I've got the sloppy fit of steel 3/4" round stock going through common 3/4" EMT conduit about 10" long for my steering, 2 of them in fact. (Changes from left-drive to center-drive.) My material for accurately and evenly filling the slop space is extremely thin aluminum sheeting called "valley flashing", comes in rolls, and is used in roofing to cover the inside bend angle of different roof sections where they meet. It's the first material after the tarpaper to get laid down, shingles follow after.
My roll is 14" wide x 10' long, other widths are available, came from Home Depot. It's as thin and workable as notebook paper, have it wrapped around the steel shaft about 3 times, ends are touched with solder so a turn won't wind it tighter. Washer at each end of the EMT keeps it inside.