There are several issues but first and foremost, the bar itself appears to be too short.
Even with the bar fully extended, I have to move the mounting plate two or three inches in order to meet up with the bar.
In that position, the plate isn’t flat against the axle. Tightening the u-bolts caused them to bend.
If I put the plate in the proper position, the bar itself appears to be two or three inches too short.
Further, it appears that the plate and u-bolts are too wide for the axle. If the u-bolts are flush against the axle in on the rear, then there is a 1/2” to 1” gap in the front. I could drill new holes in the plate and get narrower u-bolts but I hate to mess with the original design.