The CBI Aluminum Front Skid Plate for the 5th Gen 4Runner

CBI aluminum front skid black liner 5th gen 4Runner

Increase Your Engine Protection With a CBI Aluminum Front Skid Plate: Install and Review for the 5th Gen 4Runner

If you’re like me, the owner of a TRD Off-Road, or perhaps an SR5, our 4Runners come with fairly thin steel skid plates (1/16″ thickness, at most).

When it comes to engine protection, these are certainly better than anything plastic like in modern vehicles. However, all it takes is one decent-sized rock to put them out of service. The TRD Pro skid plate option is one of the most popular and is made of 1/4″ aluminum. The one major drawback of this option is that you need to completely remove it for every oil change; there are no access doors and the mounting bolts are notorious for stripping out. This leads to either yourself or a shop needing to cut the bolts out of your frame… no good.

I know there are tons of options in the way of aftermarket skid plates for the 4Runner, with a wide range in coverage and price, there is certainly something for everyone, whether it be the OEM or aftermarket.

Below, I will cover the CBI skid plate install and explain why I decided to go with the aluminum option.

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CBI Front Skid Plate (Aluminum)

CBI aluminum front skid black liner 5th gen 4Runner install

CBI offers a full suite of underbody protection for the 5th gen 4Runner that includes the front/mid-engine, transmission, and gas tank. All of these are offered in either steel or aluminum and powder coated or bare metal for the DIY’ers. The steel options are all made of 3/16″ steel (3x’s thicker than the TRD Off-Road and SR5 plates). I opted to purchase only the front skid plate in bare aluminum and have a friend prime and finish it in bed liner.

The aluminum variant is also 1/4″ in thickness, like the factory TRD Pro skid plate. The advantage here is that it covers far more surface area and has access doors for oil and oil filters. This means that you can easily change your oil without having to remove the entire skid plate, which was the main drawing point for me.

When comparing against the factory skid plates of the lower trims, the CBI front skid will cover the same area as the two separate pieces that come installed. It weighs in at 50lbs vs the 85lbs of its steel counterpart.

When it comes to deciding on steel vs. aluminum, there are a few key considerations:

  • Weight Savings – Aluminum is around 40% lighter than steel.
  • Protection Level – Aluminum is plenty for ruts and mild trails, however, steel offers more protection against the big hits for even moderate rock crawling.
  • Price – Aluminum will usually run a bit more, however, the fuel savings from lesser weight and potentially avoiding suspension upgrades to deal with the weight of steel could offset that investment.

    Tools & Materials

    • CBI supplied carriage bolts, washers, and nuts
    • Re-purposed 14mm bolts (4)
    • Re-purposed 12mm bolts (2)
    • 10mm, 12mm, 14mm sockets & socket wrench
    • 6″ socket extension bar
    • 3/4″ wrench
    • 3/16 hex key

    Step 1. Remove Front Plastic “Skid”

    Removing 5th gen 4Runner OEM plastic skid plate

    There will be four (4) 10mm bolts that will need to be removed for this portion. There is also one (1) pop clip in the center and can be removed with a flathead screwdriver.

    Step 2. Remove Front Engine Skid Plate

    Removing 5th gen 4Runner engine skid plate

    There will be four (4) 12mm bolts that will need to be removed for this front skid portion.

    Removing 5th gen 4Runner OEM rear engine skid plate

    Once all bolts are out, the skid will be held up towards the front and can just be slid forward for removal.

    Step 3. Remove Rear Engine Skid Plate

    Removing 5th gen 4Runner OEM rear engine skid plate

    Now, remove the 12mm bolts identified in the picture above. The two towards the front will require the 6″ socket extension bar in order to reach them. Set two (2) of these bolts aside as you be re-using them for the CBI skid plate.

    Step 4. Remove Front Braces

    Removing OEM front skid braces

    In order to remove the front braces, remove six (6) 14mm bolts. Set four (4) of these bolts aside as you be re-using them for the CBI skid plate.

    Step 5. Line Up Skid Plate with its Corresponding Mounting Holes

    Installing 5th gen 4Runner CBI skid plate Dobinsons

    With the OEM skid plate and braces removed, it’s time to align the new skid plate with the corresponding mounting holes. With the aluminum skid plate, this step is manageable solo. However, steel will be more challenging without a second set of hands.

    Step 6. Install 14mm Bolts in the Center Recessed Mounting Points

    Installing middle 14mm bolts on CBI 4Runner skid plate

    You will need to use a 6″ socket extension bar to install these. Loosely install these bolts, but do not tighten them completely.

    Step 7. Install Front Mounting Bolts

    Installing middle 14mm and 12mm bolts on CBI 4Runner skid plate

    From left to right, holes one and three will use 14mm bolts, whereas holes two and four will use 12mm bolts.

    Step 8. Install Rear Carriage Bolts

    Installing rear carriage bolts on CBI 4Runner skid plate

    The mounting holes will be the square ones on the rear of the CBI skid plate. These 1/2″ x 3.5″ carriage bolts will go up through the frame brace and be secured with a washer and serrated nut using a 3/4″ wrench.

    Tighten All Bolts and Nuts

    Once the skid plate and all bolts are in place, tighten down all six (6) front bolts and two (2) rear carriage bolt nuts.

    Step 9. Install Access Doors if Needed

    Oil access door CBI 4Runner skid plate

    If the oil and oil filter doors need to be installed or tightened, do so by utilizing the 3/16 hex key.

    Final Thoughts

    CBI skid plate installed on white 5th gen 4Runner

    I love the way this skid plate install turned out! I may be with the unpopular opinion that a black skid plate gives the underbody protection an understated look vs. the bright TRD pro grey (especially with red lettering). In the end, it’s your rig and you should ultimately choose whichever look appeals to you – there is no such thing as a “wrong” look!

    I’ll admit, I’m not going to make it a goal to put this skid plate to the test as my rig is still pretty much brand new and still a family hauler. However, the aesthetics and peace of mind over the thin steel ones that came installed are a welcomed addition.

    I now have the confidence that I am protected at least in this underbody section from something more substantial than branches on the road. There are two large mesh-covered breather holes on the stock skid plate that always made me paranoid that a freak accident would send something right through those and cause damage. But, I digress…

    I would love to hear what options you all are running, or even why you choose to stick with what came installed from the factory! Leave a comment below. Thanks guys!

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    2 months ago

    Sounds like no conflicts w/ KDSS and those Apex Overland recovery points? Any compatibility issues w/ a diff. drop?

    William Deschenes
    William Deschenes
    5 months ago

    I’m in the market for a new aluminum skid plate.
    Do you have pictures of the inside of the skid plate? To see how it’s made? Is it reinforced like the OKX one?

    5 months ago

    Does this setup work with a front diff drop?

    5 months ago

    Hi Ryan,

    Do you have a picture of the plastic trim installed that covers the portion of the front bumper to the new CBI skid?

    6 months ago

    Ryan, nice work and product is some of the best on market. I’ve same CBI setup and it fit my KDSS 2013 Trail perfectly. Looks like your front mount required spacers/washers and front cross member has a gap between it and new plate. You shouldn’t need those. Reverse your overlap order where you mid plate attaches to front below instead of above front plate lip. I know it is counter intuitive but it works fine sliding over rocks that way also. You will regain about 1/4 inch of lost ground clearance and will have stronger mounts without spacers.

    6 months ago
    Reply to  Ryan L

    Here is the overlap by CBI design. See how front plate is above the rear where these bolted to each other:

    5 months ago
    Reply to  Maxim

    Can you cite where CBI states this? (There are no written instructions.)

    It is very counterintuitive to create a lip in the middle. I just installed my plates with the mid-plate above front plate.

    I don’t see how the orientation you are suggesting is optimal or saves your ground clearance. I have found the opposite to be true.

    Would you please explain?

    5 months ago
    Reply to  Michael

    Pic of my orientation

    6 months ago
    Reply to  Ryan L

    You got to add that to your shopping list 🙂

    5 months ago
    Reply to  Maxim

    I ended up using longer bolts in that location to pull the plate in to the frame since aluminum will flex.

    Chris in Milwaukee
    Chris in Milwaukee
    6 months ago

    Looks nice! I’m pondering skids myself.

    Is there a companion product that will fill that gap up front to protect the cooling components? Or did you put the cover back on from Step 1?

    Questions or Comments? x