How to Clean Weld Nuts on Vehicle Frame for Hitch Installation

Updated 07/25/2017 | Published 07/22/2017

Question:

I just finished installing the curtis hitch on my car except for one M12 1.25 x35 hex bolt that I could not get to screw into the frames weld nut. I used one of the Toyota bolts I removed in place of it for now. Is that ok or do I need a new nut from you, or if ok can I get one at lowes that meets the spec. THanks

asked by: Todd N

Expert Reply:

You are best served by using the correct supplied mounting hardware for your Curt hitch # C13200. Hitch hardware is a specific grade, usually grade 5, and the hitch will be able to deliver its rated capacity only when installed exactly as specified by the manufacturer. Never use substitute hardware.

What I suggest you do is use a spray-on lubricant/solvent such as PB Blaster or WD40 in the weld nut threads. It is quite common for dirt, salt and rust to make it tough to get hitch hardware to thread properly in the weld nuts on the frame. Apply the solvent and wait an hour; then re-apply it and use a stiff bristle brush to clean out the threads. You can refer to the linked article on cleaning weld nuts.

expert reply by: Adam R