A couple observations.
The gear assemblies do not look new, I see mismatched screws. Are these gear used?
Assuming these are used I'd suspect that the "TRUNION WELDMENT" has a bent pin.
The pin can be straightened, I've done it on my retracts. The pin gets bent during a ground loop or hard hit.
I used a steal rod and drilled a hole in the end that matched the pin diameter. I used this to straighten the pin. The most difficult part is knowing how much to bend the pin.
A good digital level can be used to compare the angle of the left and right Trunion Pins.
Good Luck
Matt