Skid Plate Installation

Difficulty: 1/5

Time to install: 60-120 mins

Tools Required: Socket and Ratchet set, wrench set, Rhino Ramps or Jackstands, plus your own hardware for the rear bolt holes: bolts, nuts, washers and lock washers.

This is my installation notes of the Bold Move skid plate for 89-05 Miatas. This helps protect the Miata's front subframe. The skid plate weighs approximately 15 pounds. In comparison to the Beatrush skid plate, it's far more robust, however, it only protects the subframe. The Beatrush skid plate, while thinner, protects all the way up to the front chin of the car. Because of this it also replaces the OEM plastic splash pan, but is unable to box in the sides of the engine. I preferred to keep the plastic splash pan in hopes of keeping the lower pressure in the engine bay to keep the radiator at maximum cooling efficiency.

As you can see, my splash pan is pretty beat up. So is the subframe, because I had to replace it when a truck dropped some junk on the freeway bending the subframe!

A shot of the skid plate, fresh out of the box, with a hole cut for oil drain access. Unfortunately, it does not include bolts for the rear-most holes. Unsure if this is a problem for early 89-97 Miatas, but for my 99, there were no existing bolts to use, so I had to run to the hardware store. I purchased:

    1. Two Grade-10 17mm bolts

    2. Two nuts

    3. Two flat washers

    4. Two lock washers

Step 1, remove the 10mm bolts on the corners of the plastic OEM splash pan.



Next, the front subframe brace needs to be removed. Save two of the bolts for re-installation.

A shot of the bolt holes that will be used for your newly purchased, grade 10 bolts.

The hole alignment for the bolt installation was near perfect, but off slightly by a half millimeter, possibly because I bought a used subframe as a replacement. Use an aggressive found file or dremel to elongate holes if needed. When filing, spray the area down with WD-40 to lubricate the area. This will help keep things cool and keep filing productive. If it feels like things are slowing down, douse a little more WD-40 as you go.

Lightly install the first front 10mm bolts.

Using some of the pre-existing bolts from the front subframe brace, install the middle bolts. Notice the last end holes, the skid plate floats about 4mms below the subframe mounting holes.

Install your purchased bolts. Because there's no threading behind the subframe, use hardware to mount the skid plate to the subframe. From bottom to top, the order should be:

    1. Bolt (apply a little LocTite prior to assembly)

    2. Skid Plate

    3. Subframe Brace

    4. Flat Washer

    5. Lock Washer

    6. Nut

As you tighten, the skid plate will bend right up, flat to the subframe.

Tighten up all bolts, you're ready to go!