To fix loose Cat 1 pins, use a NEW pin, grade 8 flat washers, one on each side, locktite, a new grade 8 nut, and use the correct torque. (If you want to make a new pin out of a grade 8 bolt even better, but I have found new India manufactured pins will take the torque with a grade 8 nut) No LOCKWASHER. Look up the proper torque for Grade 8, fine thread SAE bolts in the hitch pin size and use that. (Get a bolt manufacturer's torque table on line.) You will be surprised at how high the torque is. Most pins are loose because they were never tightened to the correct torque when installed. I forget the size of the thread on the Cat 1 pins, but, for example, the JD torque table value for a 3/4 standard, not fine thread, grade 8 bolt, unlubricated is 400 ft/lbs. (I think the pin threads are larger than 3/4, but not sure) I use a 3/4 drive socket and ratchet with a 4 foot handle to tighten. 100 pounds x 4 feet = 400 foot/pounds. To hold the pin, I use a SNAP ON(Because it won't bend) 4 foot taper punch in the hole for the clip in the pin, braced on a wood block on the ground.
Once pins are tight, check them at the start of every season. Also, you will never get an implement assembled by a dealer with the hitch pins properly torqued. They do not have a large taper punch to fit the hitch pin hole and they just hit it with an air impact. Not much over 200 ft/lbs tightness there. The pins will loosen up and wallow around and, by the time you notice, the holes have to be rewelded and redrilled.
Best to always retorque hitch pins, (better yet, put on new ones. They are cheap.) on any equipment which is new to you. It is a pain to repair hollowed out hitch pin holes. Lots of attachments are ruined by loose pins.
You can tack weld the pin to keep it from spinning, but tack welding the nut does not make it stay tight and usually stretches it and loosens the torque you put on it. The mounting hole on the attachment will wear out with a welded nut which is not tight enough. The nut does not need to be double nutted. It will stay tight by itself at the proper torque and double nutting tends to loosen the inner nut and reduce its torque as you tighten the outer nut. Double nutting will conceal a loose inner nut,
You are right that the A frame on the mower should be free to pivot after the pins are torqued. If it does not, because the bushing crushes, get a better bushing at a machine shop.
435 ft/lbs from TITAN is the correct torque. Be sure to hold the pin from turning as you torque it.
As I read the comments about the two different hole sizes on the A frame and actual mower mounting frame I realize that there is one thing I need to clarify in addition:
Most bush hog type mowers are designed to have some flex in the angle of the mower so the tail wheel and back of the mower can tilt up and down to allow the back of mower to pivot up over bumps as you mow areas which are not entirely smooth. This travel is limited by using an A frame at the front of the mower which can tilt back and forth which is connected at the top to a bar reaching to an assembly near the tail wheel of the mower. This A frame is located just inside the main mounting frame for the mower which is welded to the deck. The bottoms of the A frame arms have holes which the hitch pins pass through, BUT the fit of the holes is just loose enough to allow the A frame to tilt back and forth without flopping around. This is done by a short bushing which fits over the hitch pin shaft and inside the A frame arms. If your mower is incorrectly assembled or missing parts, it is hard to figure what the correct assembly is supposed to be.
The correct assembly of the hitch pin and frames working in from the outside of the hitch pin is: (Outside working in) Hitch pin with its shoulder against the main mower mounting frame which is welded to the mower deck. (The hole in this frame is snug on the hitch pin) Next is the pivoting A frame. (The hole in the bottom of the A frame arm is LOOSE on the hitch pin) There is a bushing in the parts kit which is just taller than the pivoting A frame is thick and the bushing fits into the hole of the pivoting A frame arm with a slightly loose fit. This bushing is a snug fit on the hitch pin shaft. Slip this bushing over the hitch pin shaft and inside the hole in the bottom of the pivoting A frame arm. Next, there is a large flat washer in the kit. The inside hole is a snug fit on the hitch pin shaft. The outside of the flat washer is larger than the hole in the bottom of the pivoting A frame arm. Put this flat washer on the hitch pin shaft next. After that put on the next heavy flat washer (If they give it to you. Buy a heavy grade 8 SAE flat washer which fits the hitch pin shaft if they don't.) Last, put on the nut for the hitch pin and torque to 435 pounds. The pivoting A frame should move without binding but not flop around because it is held between the large flat washer and the outer mower frame. There should be almost no side to side play or twist. Just pivoting towards the back of the mower. If the a frame does not move, make sure the bushing is there and that it has not crushed. If the bushing has crushed at the proper torque, get a better one at a machine shop and install it. DO NOT solve the problem by backing off on the torque on the pin, as you need the full 435lbs torque to keep the pin tight, especially with the bushing and washer arrangement.
It is a simple arrangement once you have seen it installed, but confusing if you get parts in a bag or if parts are missing.
