So I've been experiencing this noise and now fairly sure it’s within the axle compartment with all the bolts that holds the stem upon which the wheel is attached. I tried dragging the right brake some to see if that might help but it did not. What made a difference was to drop the Gannon off the 3 point to allow for attaching a quick hitch. No clunking at all, low or high gearing and at a fair gallop. Quick hitch on and Gannon reattached, again clunking. Not really noticeable in reverse. In the operator’s manual for this tractor on page 55….22.Rear Axle Group I’m thinking the Gear, spur 74 as suspect but wouldn’t that still be clunking if at fault without the Gannon attached? Thoughts? Don’t really want to remove the tire and start digging into the rear case if that may not be the issue.