How to Fish Bolts for Trailer Hitch Installationby K.K. Lowell
It often seems like car and truck makers have conspired to make it difficult or impossible to install a trailer hitch. Custom fit hitches from companies such as Draw-Tite and Valley make it a lot easier, but you must still deal with blind bolt holes and fishing the bolts through. Getting a bolt in some of the holes is an exercise in futility---unless you know a few tricks.
Note the holes in the frame, which were designed by the hitch maker for the mounting bolts. It's important to be 100% certain you'll be putting the bolts in the correct holes because it's as hard to get the bolts out of an incorrect hole as it is to fish them in the correct hole in the first place.
Make a keyhole shaped loop in a piece of mechanic's wire. The loop should fit snuggly on the threaded portion of the bolt.
Push the bolt into the frame with the looped wire until it can be inserted in the proper hole. When the bolt is through the hole, a steady pull on the wire will release the bolt as the loop straightens out.
Run a piece of fishing line up through the hole when access for the wire isn't possible. Run it out the frame through a hole large enough to put the bolt through. Tie the fishing line at the top of the threaded portion of the bolt then hold the line along the bolt and wrap with a turn of electrical tape. Pull the line back through the hole to fish the bolt through.
Weld a strip of metal to the head of the bolt to fish the bolts for trailer hitch installation in areas where the hole can easily be seen but cannot be reached. Use a thin strip of metal that can bend as necessary to clear obstructions.