Dobinsons IMS Shocks - Unboxing and Toyota 4Runner Installation

Introduction

For decades, Dobinsons has been selling some of the best springs, dampers, control arms, and everything else a 4x4 might need, making them one of the most popular brands from Down Under. We’ve recently added them to our catalog and are excited to run them through our paces to see how they stack up against the competition.

After installing and trying out a few of their top-of-the-line MRR three-way adjustable kits, we were itching to try out their IMS dampers as we think they are a perfect sweet spot for the average enthusiast. Coming in at a similar price as packages like Bilsteins 6112s and 5160s, they are not the cheapest option out there, but just like the Bilstein shocks, they definitely knock it out of the park.

You may have noticed we keep referring to Dobinsons options as kits rather than simply a set of shocks, struts, and or coilovers. Although every piece of their packages can be ordered individually, they are designed to work together to make a cohesive suspension system optimized for your specific application.

Being a spring manufacturer first, their kits almost always offer a wide array of options in varying lengths and rates for the front and rear, allowing you to build a suspension that gives you the lift you are looking for while compensating for whatever constant load you may have built into it. In most cases, this also means the accompanying shocks bundled with those springs in their kits are available in different travel lengths and, in some cases, even different valving options.

The Fifth Generation 4Runner 0.75”-3.5” lift IMS kit we had the pleasure of unboxing and installing followed their usual theme as well. This particular system is available with six different front springs ranging from 0.75-2.5” of lift and up to 300 lbs of additional constant load and twelve rear springs for 0.5–3” of lift and up to an additional 1000 lbs of constant load. The included IMS struts and shocks are also available in extended and standard travel options to match the full range of available lifts from those springs.

We went with the C59-302 2.5” lift springs for the front and the C599-599 1.5” lift in the rear, both of which are optimized for a mostly stock-weight vehicle. The plan was to get to 3” of lift in the front and 1.5” in the rear for a nice aggressive, level stance.

What are the Dobinsons IMS dampers?

Dobinsons’ IMS series of dampers is their take on the traditional internal floating piston monotube damper design. Bilstein invented this design and it’s used by all the major brands including Fox, King, and Icon. Depending on the application, they are built with 50 or 60 mm pistons that offer tons of potential dampening force for plenty of support when you need it most, and their super plush tuning ensures they do not beat you up on the smaller stuff.

Various travel lengths are available. The IMS shocks offer some of the most available stroke out of any bolt-on shock or lift system of similar height; often only requiring minor modifications like extended brake lines or bump stops to make them work. They are made of super strong, 3mm thick DOM bodies that are seamless and threaded on their struts, which is a very desirable feature.

Lift Height Adjustable

You may have noticed we mentioned our particular 5th Gen 4Runner kit was capable of up to 3.5” of lift but only offers front coil springs that go up to 2.5” of lift. We opted for the extended travel front struts, which, in combination with their additional stroke and that threaded body, meant you are able to add an additional inch of lift by just moving that collar up and adding a little more preload. Since they are a steel body, that also means you can make some adjustments while they are installed on the vehicle as well. We think you should still use a spring compressor to make any major preload changes, but you can certainly get away with making some minor adjustments while on the vehicle.

Our goal was about 3” of lift in the front, so we added about a quarter inch of preload while on the compressor, and then once installed we grabbed the spanners again to help iron out some of the dreaded Yota lean. It definitely took some manpower, and an “extension” to the spanner wrench for more leverage, but as you will see from the video, we were able to get it pretty level both front and back and side to side.

Rear Height Options

This particular kit also has the option for extended travel rear shocks, and although not what we ultimately ended up installing, are probably the longest travel shock that “bolts on” to the back of your 4Runner, GX, Prado, or FJ. These shocks require extended brake lines and 3” bump stop spacers to work and will unseat just about every coil spring beside a 3” dual rate or “long travel” spring.

Since we were looking for a leveled look and did not want to limit bump travel that much, we kept things more modest with the standard-travel shocks plus their shorter rear springs, but if you were looking for the utmost in articulation for the nastiest of trails, those extra long shocks are undoubtedly worth it.

One of the biggest benefits of Dobinsons making their own springs as well as their dampers is that they develop packages that offer way more travel than just about anything else out there. More often than not, you will need to do other modifications like upgraded control arms, longer brake lines, and spacing out your bumps to either make the parts fit or, at the very least, actually use all the travel they might offer. In most cases, Dobinsons sells a solution for each of those sticking points.

Dobinsons IMS Shock Valving - Balanced, Liveable, Long-lasting

Dobinsons’ tuning makes them a real winner when it comes to quality. We truly believe many high-end suspension manufacturers have lost the plot when it comes to tuning their parts, or at the very least, how they think the end user is really using their parts. Where many brands assume their buyers are looking to skip whoops out in the desert, Dobinsons knows most drivers are running slower trails, commuting to work, and rarely, if ever, sending their steeds to the stratosphere. Ultimately, most people don’t actually want race level shocks.

Time and time again, we find the Dobinsons are just plain more comfortable in almost any situation but the most extreme. That is not to say the IMS is a soft and squishy shock. In fact, they still offer a firm, planted, and confidence-inspiring feel, but are unquestionably gentler to the old fillings than many other more expensive “Race Inspired” suspension systems.

This ethos of keeping things “Trail Oriented” rather than “Race Inspired” extends beyond their valving profile to every facet of these shocks, especially their components. Where possible, they use OE-style mounts and bushings for the longest life with the least noise, vibration, and harshness. Although serviceable like many other high-end shocks, they use seals that typically tend to last longer under more normal conditions than the seals used by other brands like Fox, King, or Icon. The combination of their easy-riding tune and low-maintenance components makes for a package that is incredibly easy to live with, despite not being quite as well equipped to take extreme abuse. The rowdier valving profiles and stiffer (and sometimes solid) mounts used by some of the more “Race Oriented” shock packages do mean they can dampen much bigger hits, stay consistent through much higher temps without melting down, and generally survive a lot more serious abuse, however, it comes at the cost of being less livable on the road and comes with significantly more frequent maintenance.

Sure, you could definitely blow out a stock top hat and burn the seals out of an IMS shock, but how many people are heinously hucking their daily driver? We would argue that most drivers like to keep their tires touching the tarmac and trail, so going with a softer and longer-lasting set of bushings, mounts, and seals is welcomed on kits like these.

Dobinsons IMS vs The Competition

Although at the top end of this particular price bracket, there are definitely a lot of popular options out there for similar money. In our experience, the popular Bilstein 6112 front and 5160 rear combo sit at the top spot in this tier of shocks. The contender is not dethroning the king in this round. However, we wholeheartedly believe the IMS deserves to share the crown.

As we touched on before, Dobinsons uses 50 and 60 mm pistons, with this 4Runner kit getting the smaller of the two. This is a small step up in piston size over the 46mm piston used on the 5160 rear shocks from Bilstein, but is a bigger step down from the 60 mm piston in the 6112s for the front, where you will most benefit from the additional dampening force provided from a larger diameter shock. Pair that with their softer and more compliant tuning, and the IMS simply does not have the all-out support of the Bilsteins.

With that said, maximum support against big hits and unwanted body motions at the expense of some comfort clearly is not what Dobinsons is aiming for with these IMS kits, so we think the downgrade in piston size is not necessarily something somebody who is looking at one of these kits should be all that concerned about.

The Bilsteins are probably the better choice for somebody with a heavier foot or who might like to haul some heavier loads, but if comfort and compliance are paramount, the Dobinson IMS should be at the top of your list. It is invariably about the right kit for the right person, so when your habits and preferences align with how the kit was designed… that’s the kit for you.

Final Thoughts

Dobinsons’ holistic approach to upgrading your suspension as well as their tight grasp of how most people plan on using their rigs, really make this IMS kit a real winner for the average Off Road enthusiast.

Even though many of us like to believe we will be ripping the desert like Robby Gordon and scaling boulders like Shannon Campbell, the reality is most of us spend more time commuting to work and cruising to campgrounds.

The IMS kits offer an easy-to-love blend of comfort and control that is perfect for how most people actually drive their rigs. There are definitely packages that are better for the hard chargers and hooligans out there (your humble author included), but if you like to keep your pace out in the dirt reasonable and still need something that does not beat you up when you are in town and on the highway, the Dobinsons IMS is right up your alley.