How to Clean Weld Nuts for the Installation of a Trailer Hitch

Select your vehicle to confirm the Trailer Hitch fit

Problem

Are you experiencing any of the following problems while installing a hitch on your vehicle?

The supplied hardware seems too big for your weld nuts
The threads of the supplied hardware do not correspond to your weld nuts
The bolt will not start in the threads of your weld nuts

Cause

Underneath your vehicle, the frame is constantly exposed to dirt, grime, moisture and salt. This gunk can find its way into the open weld nuts, or bolt holes, in your vehicle frame and harden over time, causing rust and corrosion in the weld nuts on your vehicle.

Solution

With help from a wire brush and some spray lubricant, a few simple steps can be taken to make your weld nuts clean and grime free, ensuring an easier installation of your trailer hitch.

Step 1: Spray bolt hole with a lubricant like Blaster Lubricant or WD-40. Let the lubricant sit for a minute, allowing it to penetrate and soften the grime and corrosion.

Step 2: Scrub the lubricant-coated bolt hole with a wire brush to loosen corrosion and grime. Rigorously run the brush in and out of the bolt hole.

Thread Bolt in a Few Threads Into the Weld Nut

Step 3: Repeat steps 1 and 2 multiple times or until the bolt can be twisted in a few threads deep.

Using a Ratchet to Thread Bolt In and Out of Weld Nut

Step 4: Use a ratcheting socket wrench to run the bolt in and out of the bolt hole.

This lets you use the bolt's threads to loosen the remaining corrosion embedded deeper within the weld nut
Ensure that the bolt hole remains lubricated while ratcheting the bolt in and out
Slowly, you will be able to work the bolt until you can thread it completely in and out of the weld nut

Once a bolt can be threaded into each of the weld nuts on your vehicle's frame, you can begin your hitch installation knowing that you will not encounter any resistance when bolting up the hitch.

To watch a video demonstration on cleaning out your weld nuts, click here.

Updated by: Raymond P.

Last updated: 6/29/18

Questions and Comments about this Article

Beau 8/25/2020

This article doesn't go as far as it should to reveal the stages of work in order to remove hardened deposits within the weld nuts (threads). I followed all the steps in the above article and it had zero effect on my vehicle, therefore I had to research other methods to remove the deposits. The simple method of using a ratcheting socket wrench did not provide enough torque. To remedy this I used my impact driver to deliver the torque needed to break the hardened rust & deposits. For the other weld nut, I needed to tap (tap & die set) the threads as a means to break the rust