ARB Differential Breather Kit Install & Review

If you plan on doing some wheeling (even casual wheeling), you will eventually experience a water crossing. It’s a very fun part of this dirty off-road life!

Sadly, our Tacomas aren’t properly equipped from the factory to handle these in stride, that’s where the ARB differential breather comes in.

Note: This kit fits many different Toyotas. Confirm fitment before buying.

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• ARB Differential Breather Kit: Check Price

Product Overview

There are certain precautions you can take in building a safe and reliable rig; one of which is a differential breather.

Your truck has differentials (front and rear if you have 4WD) that need to “breathe”. For the Tacoma, there is a one-way “breather” valve on the top of your rear one. This can cause issues during water crossings when you submerge it.

The risk of ingesting water into your rear differential is very real and very costly. The damage will not be immediately apparent and will take a while to manifest. By the time it is discovered, the damage can be extensive.

Lucky for us, the ARB kit is a relatively easy way to minimize this risk.

Installation

Included in the kit are all of the fittings and hardware needed to install the breather, with minimal tools required.

Tools & Materials

• 10mm Socket & Driver
• 13mm Open-End (Box) Wrench
• 14mm Open-End (Box) Wrench
• Tubing Cutter (Or Razor Knife)
• Wire Cutter
• 3mm Hex Key
• Phillips Head + Power Drill

Step 1. Partially Assemble Manifold

Start by gathering the manifold and the fittings.

The provided four-port manifold ships unassembled and offers several options for us. For the purposes of this installation, we will be using one port as the input from our rear differential and the filter outlet port (located on the flat face of the manifold).

The remaining three ports will be blocked off with the supplied threaded plugs (use your 3mm hex head to install the threaded plugs).

The additional ports allow you to scale the system in the future, should you need to add a safe venting solution elsewhere.

Step 2. Remove Driver’s Side Tail Light

Picking a suitable location for the breather is key to maximizing the potential of the system. If you mount it too low, you will face the same issues as you would with the stock breather. For our installation, I opted to mount the manifold in the driver-side tail light bucket. It is easily accessible and places the filter fairly high above the rear axle.

Start by removing the uppermost and lower 10mm bolts from the inside of your tailgate. These bolts hold the taillight in place. Once removed, grasp the taillight firmly and pull it straight out. There are two alignment studs that further secure the taillight in the housing and it takes a little force to remove the tail light, especially the first time.

Step 3. Mount Partially Assembled Manifold

Lay the taillight on the tailgate (the wires will be long enough to reach) and take a look at all of the real estate you have to mount the manifold and filter.

Find a suitable location for the partially assembled manifold. We will be mounting the manifold and filter right in the middle of the bucket. I have the Meso Customs Total Tails upgrade, so I have some extra wiring in the buckets already. Yours may not look as crowded as mine.

Once you ascertain the mounting position, secure the manifold to the inside of the bucket with the supplied self-tapping screws. These are “sprint point” screws and they will go through the sheet metal when you drive them with a power drill and Philips head bit.

Step 4. Remove Stock Breather

Now, let’s get under the truck and run some tubing! Get your 13mm open-end (box) wrench, 14mm open-end (box) wrench, tubing, and zip ties ready, you will want them with you for this!

The first thing you need to do is locate the stock breather. It will be on the top of the differential, closer to the driver-side rear wheel, and has a 14mm nut as part of the housing. Locate it and remove it.

Make sure you clean off any dirt or caked-on mud around the breather first, we do not want to introduce any of those contaminants inside.

Step 5. Install Supplied Tubing Collar

Once the stock breather is removed, install one of the supplied slip-fit tube fittings. The fitting has a 13mm nut as part of the housing and will thread right into the rear end. Be sure to snug it down but don’t over-tighten it.

You will notice the fitting has a spring-loaded plastic collar in the metal housing. This is what will keep the vent tubing firmly in place once it is attached.

Step 6. Connect & Route Vent Tubing

Attach one end of the supplied vent tubing to the plastic collar and push firmly down. The collar will slip and then bite the tubing. Try and pull it straight out, if you push hard enough, the tube will now be held firmly in the fitting.

Now, we are going to route the vent tubing. You will see a few lines coming off the rear end and running along the frame. You want to find a sensible routing solution, keeping in mind that the rear end moves and articulates, especially if you are lifted and wheeling!

Leave some slack between the differential fitting and the first mounting point. I left a 6” coil of tubing between the rear end and the first zip tie. Then, follow the driver-side frame rail back to the opening under the driver-side tail light bucket. You will see some wiring running this exact path. Attach a few zip ties to keep the vent tubing out of harm’s way and tucked safely away! Clip the ends of the zip ties with your wire cutters to keep the installation nice and neat.

Route the tubing up into the taillight bucket (following the existing wiring path) and pull the slack through the taillight bucket.

Step 7. Connect Vent Tubing To Manifold

This kit comes with a lot of tubing and you will have quite a bit left over. Before you cut the tubing, make sure you leave a few inches of slack in the taillight bucket. Use a tubing cutter or a sharp razor knife to cut the rigid vent tubing.

Important: Do NOT use a pair of wire cutters, you WILL crush the end of the tubing and it will NOT sit properly in the slip-fit collar.

Once you have cut the vent tubing to size, insert the cut end into the collar of the manifold we mounted earlier. The procedure is the same as the fitting on the rear end, push firmly and test the connection once you feel it click into place.

Step 8. Attach Manifold Filter

Once you have slipped the vent tube into the manifold, thread the filter assembly into the threaded hole on the face of the manifold. Keep in mind that the filter is plastic and the manifold is aluminum; do not over-tighten the filter as you run the risk of stripping the threads on the filter housing.

Step 9. Reinstall Tail Light

Install your taillight, making sure nothing is binding up or in the way. Test for functionality, making sure it operates as it should.

Now, let’s get back to that water crossing! With the ARB differential breather kit installed, you can confidently cross that stream without the fear of costly water ingestion!

Final Thoughts

Your truck is a big investment and a source of much enjoyment. Simple precautions like the ARB differential breather kit are a great way to ensure you will continue to enjoy your truck, through almost all conditions, for years to come!