Ford Aerostar transmission crossmember bushing.

The Ford Aerostar has 4 bushings on the lower crossmember under the transmission. This assembly is designed to be replaced as an entire unit from the factory. Replacement parts for this vehicle are non existent, and junk yards don't save parts like this. Considering its age, a used part will probably be damaged, and unusable. 3D printing is the next best alternative. These parts are replaceable with a little time & effort. You will need a rotary grinder, cut off wheels, two pieces of 3/8" X 4-1/2" NPT black pipe cut down to 4-1/4", four lock nuts which are used on electrical fixtures to go on the end of the pipes, two washers, two 7/16" X 6" bolts, and nuts. 5-1/2" length will also work but is hard to find in this size. It's possible to resize the bushings to make them a little larger so that a washer isn't used but it might be harder to install since it will be a tighter fit with less room to twist. 60% infill with 300 height is recommended with TPU filament. I used CCTree 100A shore hardness TPU. Place one lock nut on the pipe. Tighten it all of the way down, then cut off a 1/4" above the nut. This will be locked into place. The opposite side will have a removable nut, so assemble both bushings, then lock them into place.