Reviving a Tired 4Runner from the Ground Up

The third generation 4Runner is a proven and respected solution for exploration. Variations of the model are used internationally under names like Surf, Hilux SW4 and Prado. In late 2012, our team purchased a stock and well cared for unit with just over 150,000 miles. Our first goal was to address any outstanding service needs, but as expected with a Toyota, there were few. However, the tires were done and the suspension was sagging and tired.

Displaying both a lean and a rake, the rear springs were shot from years of use in Northern Arizona. The shocks were also toast providing no damping effect causing the truck to sway and pitch with every road input. It was time to put this classic overland choice on solid footing and include some new shoes in the process.

In our opinion this is where aftermarket suspensions really shine, breathing new life into older vehicles that are still full of potential. Although many have done it, it seems ironic to take a brand new vehicle and replace the suspension. While the OEM engineers spend thousands of hours designing the stock suspension, they are faced with far too many compromises. The suspension must be cost effective, carry a moderate load and provide a comfortable ride. These attributes are almost always at odds, resulting in dull performance, limited payload and a short service life. With our project 4Runner, the team wanted to remove all of these limitations and breath new life into this iconic vehicle.

There are several aftermarket suspension options available for the 4Runner, but that list was shortened quickly once we outlined the planned use of the vehicle and the intended load requirements. Although there are several high-quality choices, only ICON Vehicle Dynamics has specialized in optimizing the performance of late model Toyotas. Although not a particularly big company, they take a different approach and focus on rapid development on the desert race circuit, then model those results for the end consumer. The outcome is nothing less than astounding. Having used ICON suspension for decades, both in long-distance overland trips (one suspension traveled from the Arctic Ocean to the Darien Gap) and racing applications, we knew that Icon was the logical choice.

The ICON suspension provides both lift for additional ground clearance, and improved performance with a load at both high speeds on pavement and varying dirt conditions. A lot is being asked of the suspension, including the requirement of full articulation, while also being comfortable and secure on the road. We would also demand this performance with wide variabilities in load, from unloaded daily-driver duties, to fully loaded adventures down the length of Baja.

For the front of the 4Runner we went with the ICON Extended Travel Front Coil-over Shock Kit paired with their Tubular Uniball Upper Control Arm System. The Coil-overs are adjustable from 0”- 3” with a 2.5” nitrogen shock charged to 250psi and flutter stack compression valving. The upper control arms allow for improved wheel travel and help to prevent premature ball joint wear.

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For the rear we used the ICON 2.5” Remote Reservoir Shocks with Old Man Emu medium springs, #2906. Note that the OME were recommended by ICON as they don’t make a rear spring for the 3rd Gen 4Runner.

(The comparison in size is almost comical!)

The installation started with the rear axle, which we expected it to be easier, and a chance to ease into the project. The rust-welded shock mounting bolts quickly proved that assumption wrong. In order to get each shock out we had to use an air powered sawsall and a cutting wheel to cut off the top mounting bolt from the shocks. Once shocks and springs were removed the installation was straightforward. The most difficult part with the rear shock installation is finding a place to mount the remote reservoirs.

ICON makes a piggyback reservoir shock for the 3rd Generation 4Runner with a 5” reservoir mounded directly to the side of the main shock body. The shocks we are using however include the CDI system incorporated into the shocks remote reservoirs which requires an additional two inches to accommodate the internal valving system so the reservoir is 7” rather than 5”. This additional 2” and the surprising lack of space under the back of a 3rd Gen made finding a suitable mounting location one of the most difficult parts of the install. After a few test locations we decided on placing the reservoirs on the outside of the frame rail to the rear of the tire on each side.

 

Installing the front coil-overs require the sway bar to be disconnected and the lower control arm assembly to be pushed down as far as possible. This is easy for the standard coil overs but for the extended travel model we found it necessary to disconnect the upper control arm, and drop the hub assembly down completely. As we were also installing the ICON upper control arms this was all part of the process.

After removing the stock upper control arm the ball joint will need to be pressed out of the spindle. We used a ball joint separator for a large Dodge truck, with a few modifications to the tool and an impact gun, the old ball joints easily popped out. This was a huge learning process. When removing the first stock ball joint we spent an hour beating on it with a small sledgehammer and using every other implement of destruction we had at our disposal. It was incredibly frustrating and we were amazed that nothing broke unintentionally. After a break and some research to find the right tool for the job, the second ball joint was removed in less than ten minutes! Note, when using the ball joint separator you will need to grind off the tapered spindle sticking out of the ball joint. This will provide a flat surface for your separator to push on, and it’s always fun to make sparks!

Installing the front coil-overs is as easy as three bolts at the top and one at the bottom. Be sure to follow the included instructions and locate the bottom spacers properly.

For the upper control arms, you will need to remove the battery and battery tray on the driver’s side and gently move one of the AC lines on the passenger side about an inch to allow for removal of the one long bolt holding the arm on. The new arms come with impressive bushings and large washers that need to be stacked in order and aligned with the bolt. A note of caution: As with any DIY installation, be certain to go back and re-torque any bolts and nuts after an initial test drive. This is a common oversight reminded by ”what’s that funny sound?”

So far, we have driven 2,500 miles on the ICON suspension, including everything from high speed on the interstate to both maintained and unmaintained dirt roads, washboard, woops, and moderately technical rock crawling. We have pushed the limits in packed dirt, gravel, sand, mud, and rock. At this point the only change we plan to make is to increase the load capacity of the OME rear springs. With the addition of a drawer system, refrigerator and full gear we have exceeded the load capacity of the #2906 springs. We will also continue to fine-tune the ICON CDI adjustments, a surprisingly useful and effective feature. We have found the adjustment particularly beneficial as we fill the rear cargo area, the rear suspension of the 4Runner seeing the greatest load variation.

We are pleased with this new combination of Falken Wildpeak tires and the ICON suspension system. The increased articulation and rock-solid damping has greatly improved traction and stability. An added bonus the 4Runner responds much better in the twisties and during “spirited” driving.

As a testament to how the new tire and suspension combination has increased the capabilities of the 4Runner; on a recent trip to a moderately technical trail we found ourselves airing down at the trail-head among some seriously modified Jeeps on 37” tires. As we finished airing down and rolled onto the trail ahead of them we witnessed sighs of frustration anticipating a day of being stuck behind the little Toyota! After a few miles of obstacles and challenging terrain we had to stop and wait for a few vehicles going slow ahead. As we waited, the Jeep group from the trail-head pulled up along side, asked us what we were doing and invited us to go and run one of the more challenging branches of the trail system with them!

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