Quick Guide to Trimming the Defender Wheel Well

Trimming the Defender Plastics is not so black and white as it can vary depending on lift, tire size, offset of wheels, and width of the tire. To add more to the mystery, not all tires are made the same. For example a bfg km3 mud terrain 35×12.5 r18 is actually 34.5” inches in diameter. A Mickey Thompson baja boss A/T 295/70r18 is classified as 34 but is actually 34.5” inches in diameter as well. We recommend that you do not use a general tire size calculator to figure out what size your tire is, rather, visit the manufacture’s website for more detailed sizing of their tires.

Thankfully no trimming is needed in the rear.

Trimming in the front is as follows.

Starting from the bottom of the front bumper plastic, mark 1.5 inches from the edge. You will then merge it to the top corner as shown on the picture.

Trimming the front liner for fitting up to 35s

First we cut off the two vents marked with the X

This is what it will look like after cutting the vents off

Flip the liner over and trim this edge off between the red lines.

This is what it will look like after trimming the edge off

Now trim this edge off

This is what you’ll have after you trim the edge off

Cut two slits as shown. DO NOT CUT FROM EDGE TO EDGE! You just want to make 2 cuts a couple of inches long. You’ll then use a heat gun, heat the area between the cuts, and fold the crease in. Check out the following picture for a better understanding

This is what it should look like after folding the crease in.

Cut out the area marked in red.

Now move on to your bumper, after the trimming and modifications have been done (1.5″ of trimming off and coolers have been relocated) locate the bulge and make another hole as circled. You can use a pick to make stab a hole in it or a drill bit. We used a pick as its easier.

Make another hole indicated by the red dot.

Wrap a zip tie as shown around the bumper retaining bracket on the fender.

Use the holes and zip tie, to Zip tie the front fender liner onto the bumper. This picture shows how it will look installed.

For the top we used push pin clips to hold the rear liner to the front liner.

Here’s a better picture of the clips.

If you can’t source push pins. You can use zip ties.

The rear of the fender depends on the lift you go with. If you go with a 4inch sub frame drop or bigger you will most likely not need to trim or do a minor trim. If doing a lift with lift rods or a 2inch subframe drop, you will want to trim about 1/2 of an inch from the bottom of the rear fender plastic and merge it to the top as shown below. Trimming the rear pinch welds will be necessary. You will need to remove the black metal shield from the wheel well as well (no pictures available of the shield at this time.)

Here’s a picture of the lower fender plastic and trimming demonstration

Compare these pictures with yours. You may not need to trim as much or you may need to trim a bit more. Depends on your tire size and wheel offset. Reinstall your wheel and tires, set the vehicle on its tires in access mode and turn left to right to confirm no rubbing. Best to have a second person turn the steering wheel while you watch. Once the trimming is satisfactory, you can reinstalled the rear liner and zip tie it securely.