Spikey Jumbo Washer For Wrangler Heat Shield Foil

This is a large, spiked washer for fastening the heat shield foil to the subframe of a Wrangler JK (and others). It sits under the stock 10mm bolt and provides significantly more surface area (and spikes!) for holding the foil in place.

Why:

When offroading, rocks, tree branches, and other annoying things can get caught on the heat shield foil and tear it out from under the little 10mm bolts that hold it to the subframe. Even after persuading it back into place, it can still bend again and end up rubbing on the front driveshaft or other components.

This washer adds a lot more surface area to the tiny stock metal washers. It also adds spikes to pin down the foil, and flexes slightly to conform to the curved frame surface.

Printing:

This is going to be bolted to the underside of your vehicle, possibly close to the exhaust pipe. Print it out of the toughest material you can find, with solid infill. I used a high quality glass-filled nylon (Zytel 3D12G30FL BK309), which has held up fine for the last few weeks. Don’t print it in PLA, you will have a bad time.

Installation:

Take out the stock 10mm bolt and screw it through the jumbo washer. Add an additional metal washer to the front side (important, since it sandwiches the plastic washer between two metal washers and allows it to be tightened down). Coerce the heat shield foil back into position and over the screw hole, and screw the washer with bolt back in. Tighten it down to one ugga dugga (I don’t think the exact torque spec matters much here).