Since our Thule Hitching Post (4 bike) would not fit in our 2" receiver, we had to buy an 8" to clear the 35" spare & the Aluminess box. Worked fine until we went off road... and we realized the slop in the 2" receiver was creating a big shock load on the rack, due to the excessive play.
I ended up with this fix, which cost about $15 in parts/tools from OSH:
1/4" x 20 tap
sm bottle thread cutting fluid
4 - 3/4 x 1/4" stainless bolts, lock washers & nuts
I drilled the tap hole in between the rec pin hole and the end of the FORD rec, so there would not be any interference with a locking rec pin. A hole was drilled both right & left side. Two additional 1/4" holes were drilled under the rec hitch bottom, spaced out evenly.
Tap each hole.
Throughly clean each hole.
Affix a 1/4" nut onto bolt, screw down half way, then add a lock washer.
Then insert each bolt and screw into hole till bolt face meets flush with interior of hitch mount.
Insert hitch extension & pin (or lock pin)
Tighten left & right screws till the rec extension evens out in the Ford hitch.
Once snug, then back down the each 1/4" nut onto the lock washer.
Tighten two bottom 1/4" bolts in same fashion to take out any play. Since there are two points of contact on the bottom, these bolts will prevent the extension from yawing front to back.
Not sure if anyone else has this problem. This is a cheap and easy fix.
EDITED: Added Pictures