Fender Liner Push Back & Trimming on 4Runner

Fender Liner Pushback and Bumper Cut on 5th Gen 4Runner

When you buy bigger tires, you may need to prepare for cutting and trimming. Although we wrote a previous article on cutting and trimming, we are still getting a few questions about how to cut and trim fender liners.

We also wrote another article on cutting the bumper, but this was after a few modifications, not directly from a stock 4Runner.

We heard a few questions recently from users looking for exactly where to put holes in the fender liners and exactly where to cut the bumper. Because of this, I thought I would throw together a quick step by step on pushing back your fender liners and trimming your bumper. Hopefully, this overview will help everyone with a stock 4Runner start the trimming process.

We just got new Treadwright Guard Dog MT (Mud Terrain) tires (285/70R17) and they were rubbing so we needed to make a few adjustments. This 4Runner is currently running the Falcon Tow Haul Suspension which gives us 2″ of lift in the front.

The tire size, 285/70R17 is a common size that many owners make the jump to on the 4Runner so this overview will work for many of you out there.

Common Questions: 

• What tire and wheel will fit without trimming?
• What is the largest tire I can fit without rubbing?
• Will XZY brand/model 285/70R17 fit without rubbing?

To answer all of these as simply as possible, almost all 285/70R17 tires are going to rub. And, pushing back your fender liners along with trimming your bumper is not that big of a deal.

If it’s resale you are concerned about, most people buying your 4Runner aren’t going to care about a 1″ strip of bumper you had to cut off.

If it’s the actual process of cutting and trimming you are concerned about, it’s actually really easy. All you really need is some tape and a Dremel.

Either way, if you want to run 285/70R17 tires, you are more than likely going trim. This whole process is really simple and as long as you are somewhat handy, you should be fine. The next common size down would be 275/70R17 and with that tire, you are probably in the clear but you still may have slight rubbing. If you go with a 275/70R17 and end up with trimming, this guide will work for you as well.

If you do not want to risk rubbing and trimming, 265/70R17 is probably going to be a good choice.

Tools & Materials:

• Utility Knife/ Exacto Knife
• Cordless Dremel kit
• Protective Eyewear
• Automotive masking tape
• Red Sharpie
• Plastic Pry Tools
• Metric Sockets: 10mm
• Ratcheting Drive 1/4″, 3/8″, or 1/2″
• Drill driver
• Drill bits: 1/4″ bit

Step 1: Remove Bolts and Bottom clip

Start by removing the two lower 10mm bolts that hold the fender liner to the bumper. Also, remove the plastic tab that holds the center bolt into place. This will help give you a better perspective of where to punch a new hole when you push the fender liner back.

Step 2: Drill the first new hole

Pull fender liner out and then push it back into the bumper as much as needed in order to clear the tires. For the 285/70R17 MT tires, we are pushing our fender liners back about 1.5″ – 2″ from where they sit at their factory location.

There is no exact science to this. Use your best judgment, punch a hole and then go for a test drive after everything is said and done. If you are still rubbing, go back to the drawing board.

Put your tab/bracket back in and attach the bolt into your newly punched hole.

Step 3: Drill the second hole further towards the front

Once you have attached the first bolt into your newly punched hole, you can measure and mark the second hole closer to the front of the 4Runner.

Mark a hole with your red sharpie, remove the fender liner, and drill your new hole. At this point, you should have two new holes in your fender liner.

Our new holes bought us about 1 3/4″ of clearance which was enough for on-road use, so far. We have not tested the truck off-road and may need to come back for some adjustments here.

Step 4: Fender Liner Push Final

Tighten all the remaining bolts into place. Your fender liner should now be sitting much further up in your bumper.

Step 5: Prepare Dremel for Cutting

The Dremel’s plastic cutoff wheel is great for cutting the body of the 4Runner.

Step 6: Tape Bumper and Trim with Dremel

Everyone will have a slightly different cut but there’s a consistent line I have followed on our last three 4Runners. I lined up the bottom tab in the foremost position to the first tab on the inner fender liner. This will take off about 1.5″ at the bottom and gradually work it’s way up towards the top which will give you a smooth transition line.

Final Thoughts?

Whether you want to admit it or not, if you want to run bigger tires, you are going to have some trimming to do. This 285/70R17 (32.71″) tire is a great option for most 4Runner’s and it’s probably the max you want to go unless you are prepared to make even deeper body and wheel well adjustments.

So what can you expect for trimming? 

• 285/70R17 (32.71″): Expect to trim (seen here)
• 275/70R17 (32.16″): Possible trimming (if any at all)
• 265/70R17 (31.61″): No Trimming (factory tire size)

You have another tire size you have questions about?

Go to Tacoma World and check out their tire size calculator. If your tire size approaches the 32.1″ area, expect to trim.

If you want to see what it takes to trim 34″ tires, check out this article.

If you want to see what it takes to trim for 35″ tires, check this one out.