Yep, it sounds like a U joint or rubber coupler issue, can you get underneath to look for rust colored dust around the U joint ( center this is proof the U joint has gone bad. Or check out the rubber couplers at the front and rear of the shaft. You don't have to get the shaft balanced when doing the work, you can replace the couplers with normal tools, but the U joint will need to be pressed in and out. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.
Image (Click to make bigger)
Saturday, June 24th, 2023 AT 10:56 AM