Choosing the right performance off-road shocks for your Tacoma or 4Runner can be challenging, especially with so many variables based on your vehicle and off-roading style. In the past, you had to pick between ride quality and shock performance, often settling for one at the expense of the other.

But with AccuTune Equations, you can now have custom-tuned shocks tailored to your Toyota’s weight, terrain, and personal preferences. This means you can choose the brand, size, and configuration you want, and still get the ride quality you’re looking for.

Now, when selecting shocks, there are three key factors to consider:

1. Ability to make proper damping force

2. Heat capacity

3. Durability

Why Does Damping Force Matter on Tacoma Shocks?

A Brief Background On Shocks:

Damping force refers to the amount of resistance a shock provides at a given shaft velocity. This force is generated when oil flows through the ports in the piston and is restricted by round disks that act as springs.

As shock diameter increases, the amount of oil that must flow through the piston also increases, which naturally leads to higher damping forces. Because of this, each shock size has an optimal range of damping forces where it performs most effectively.

Damping Force & Front IFS Coilovers:

The front coilovers on Tacomas and 4Runners are mounted about halfway up the A-arm, which means the shocks move at half the speed of the wheel. Since the shock’s movement is slower, it produces half the force. Additionally, being mounted halfway up the lower control arm means that only half of the damping force generated by the shock actually reaches the wheel.

As a result, the front shocks on Toyota 4x4s deliver only 25% of the damping force to the wheel compared to a shock mounted directly to the wheel. This means that front Tacoma and 4Runner shocks need to produce roughly four times more damping force than the rear shocks.

This is why 2.0 shocks often aren’t big enough for the front of these vehicles. While there are valving techniques that can make shocks stiffer and shock designs that naturally create more resistance, aftermarket 2.0 shocks are generally not built to handle the forces needed for the front of a Tacoma or 4Runner.

Yes, it’s possible to make them work, but when shocks are forced to perform beyond their natural design, it can result in harshness and a reduced lifespan. In fact, many undersized shocks are overly soft, resulting in a bouncy, Cadillac-like ride.

         

Summary:

Serious off-road driving requires serious damping forces. Shocks that are too soft can cause frequent bottoming out and result in a bouncy ride off-road.

For the front shocks:

• 2.0 shocks are sufficient for stock weight Toyotas used primarily for on-road driving and slow-speed off-roading, such as hunting, fishing, and casual trail riding.

• However, for heavier Toyotas or for high-speed off-roading, such as fire roads and desert running, 2.5 shocks are necessary to handle the increased demands.

For the rear shocks:

• 2.0 shocks are generally enough for stock weight Tacomas and 4Runners used for everything from on-road driving to pre-running.

• Once you add full overland gear, like skid plates, bumpers, and a roof-top tent (RTT), you’ll need to upgrade to 2.5 shocks in the rear as well to maintain proper damping.

What is Heat Capacity and When Does it Matter?

Heat capacity refers to a shock’s ability to withstand intense off-road driving without fading, leaking, or experiencing significant wear. When considering heat capacity, two factors are key: the amount of oil and the speed of heat dissipation.

The amount of oil inside the shock determines how much heat it can absorb, while heat dissipation refers to how quickly the shock can release that heat. Larger diameter shocks typically hold more oil and have more surface area, providing better heat capacity.

However, companies like Fox and Icon make aluminum-bodied 2.0 shocks with 5/8″ diameter piston rods, which help increase oil capacity and improve heat dissipation, even in smaller shocks.

When is Heat Capacity a Factor?

Heat capacity becomes critical when driving on rough roads at high speeds over extended periods. For example, washboard roads create rapid shock movement, generating significant heat. Similarly, large whoops can also cause a lot of heat buildup when driven at speed, as the shocks use their full stroke very quickly.

In general, any terrain that causes rapid wheel movement—whether from washboard roads, whoops, or other challenging surfaces—places high demands on the shocks and requires excellent heat capacity to prevent performance loss.

Summary:

Tacomas and 4Runners work well with 2.0 shocks for slow-speed off-roading and about 5 minutes of hard run time on demanding terrain. This 5-minute time frame is a rough estimate, assuming the terrain is consistently rough and the speed is continuously high.

With the increased oil capacity, 2.5 shocks can handle about 15 minutes of hard run time before they start fading and their lifespan begins to shorten. However, adding extra weight—such as bumpers, gear, or other modifications—reduces run time because it requires more damping, which generates more heat.

If you’re a light wheeler exploring the backwoods with your 4Runner, 2.0 shocks will manage the heat. But if you’re blasting through dunes for an afternoon in your Tacoma, you’ll want to step up to 2.5 shocks, as they’re better equipped to handle the heat generated by those conditions.

What Influences Durability?

Shock durability is dictated by the size of the shock, quality of material, and reservoir configuration.

Size Matters For Hard Use:

As mentioned earlier, larger shocks naturally produce more damping force. This is partly because damping is directly related to the cross-sectional area of the shock, so larger diameter shocks operate at lower pressures. Lower pressures are easier on the seals, which helps extend the shock’s lifespan.

Additionally, larger shocks are less likely to exceed their designed operating temperature range. Running a shock at temperatures above its intended range doesn’t always cause immediate failure, but it does lead to the hardening of rubber seals and reduces the lubricity of the oil. This results in a shorter lifespan for the shock over time.

Quality of Materials:

We aren’t going to dive into the specifics of each brand here, but there are differences between the quality of materials used in each brand.

See our Fox vs King: 2.0 Coilover Shock Comparison article for more info.

Remote Reservoirs – Not Just About Cooling:

While it’s true that remote reservoirs increase oil volume, which enhances cooling and heat capacity, this isn’t their primary purpose. The main reason for remote reservoirs is to reduce the shock’s operating pressure. When the shock shaft moves into the body, it displaces oil, which increases the nitrogen gas pressure. Higher pressures cause increased friction and wear on seals, ultimately reducing ride quality.

In an IFP shock, there is a single cylinder that contains the piston rod, oil, nitrogen, and the Internal Floating Piston (IFP), which separates the oil and nitrogen. This in-line configuration leaves little room for nitrogen, which means the nitrogen charge that starts at around 200 psi can exceed 600 psi when fully compressed. Although 600 psi isn’t too problematic, when the shock heats up, the oil expands, and pressures can quickly skyrocket. Additionally, IFP shocks are often sealed during assembly, which makes them non-rebuildable.

On the other hand, remote reservoir shocks have a separate cylinder dedicated to holding nitrogen, offering substantially more volume. This design maintains consistent pressure, even when the shock heats up, and also requires separate nitrogen charging, making them rebuildable.

Stay tuned for an upcoming article on this topic!

Note: In these pictures, the nitrogen space in an IFP shock is typically much smaller, while the nitrogen space in a remote reservoir shock is much larger (often 90% of the reservoir). These shocks were cut away for display, so some parts have been artificially moved for illustration.

             

Summary:

IFP shocks are a great budget option for street use and slow-speed off-roading. However, they are not ideal for high-speed off-roading on Tacomas and 4Runners due to their construction, which doesn’t provide the durability needed for demanding conditions.

Remote reservoir shocks, on the other hand, offer better ride quality and long-term durability compared to IFP shocks. They are better equipped for hard use and demanding terrain, making them the preferred choice for more intense off-roading.

What Do Compression Adjusters Do & Do I Need Them?

There are three types of compression adjusters on the market, low speed, high speed, and mid speed. Each one is designed to tune a specific performance characteristic of the vehicle.

Low Speed Compression Adjusters:

Low-speed compression adjusters are used to fine-tune handling, g-out, and slow-speed bottom-out performance. Typically, low-speed compression adjusters use a needle and seat, which allows a small amount of oil to flow freely into the reservoir. Once the oil reaches a certain speed and pressure, it then flows through a separate set of spring washers into the reservoir, activating the high-speed circuit.

High Speed Compression Adjusters:

High-speed compression adjusters are used to fine-tune harshness and compliance during large hits, such as potholes, whoops, and fast speed bumps. Typically, these adjusters work with the high-speed spring washers mentioned earlier, allowing you to adjust the pressure at which oil begins to flow through the discs. By requiring higher pressure, you can increase the high-speed damping, making the shock more resistant to large, fast impacts.

Mid Speed Compression Adjusters:

Mid-speed compression adjusters influence both low-speed and high-speed compression, depending on the adjustment setting. When fully open, they have a slight effect on high-speed compression, but when fully closed, they have a significant impact on low-speed compression, with each adjustment making a large change.

Mid-speed compression adjusters function similarly to an extremely large low-speed compression adjuster. When fully open, they allow a large amount of oil to flow freely. When fully closed, they restrict oil flow completely. Oil that doesn’t pass through the adjuster instead flows through a set of spring washers.

Summary:

Compression adjusters provide an easy, external way to change the damping of your shocks. They’re especially useful if you’re adding weight for trips, are particular about ride quality, or want to firm up on-road handling.

• Low-speed compression adjusters are great for both on-road driving and all types of off-road driving.

• High-speed compression adjusters are most beneficial for high-speed off-roading.

• Mid-speed adjusters are less impactful than low or high-speed adjusters but still offer useful tuning for both on-road and off-road driving.

You can read more about the Fox & King Compression Adjusters here:

How Fox DSC Dual Speed Compression Adjusters Work

How King Compression Adjusters Work

Are Upper Control Arms Necessary For My Tacoma or 4Runner?

Stock upper control arms on Tacomas and 4Runners are often the first point of binding when the suspension extends. Replacing them with tubular or billet control arms can add about one inch of droop. While an extra inch of travel might seem small, it’s significant, especially since many lifted Tacomas only have 2-3 inches of droop. That extra inch can make a huge difference.

Without enough droop, the shocks will clunk hard against their extension stops, making the ride feel very harsh, especially on potholes, washboard roads, or any bump requiring more than two inches of movement. When the wheel lacks downward travel, it can’t properly follow the terrain, causing the chassis to jerk down into the hole, and then bang back hard on compression when it hits the obstacle’s face.

With sufficient down travel, the tire can smoothly follow the contour of the road, providing a much more controlled and comfortable ride.

Summary:

If you are lifting your Tacoma or 4Runner more than 1.5″ it is necessary to install an upper control arm to get the full benefits of the upgraded shocks.