ARB MT64 Coilovers & Shocks: Tacoma, Tundra, F-150 Guide

If you're shopping for a real performance suspension on a 2024+ Toyota Tacoma, 2022+ Toyota Tundra, or 2021-2024 Ford F-150 and you've spent any time in the forums, you've already noticed something: the conversation always ends up at the same brands. Fox 2.5. Bilstein 6112/8112. ICON 2.5. And, more and more often over the last 18 months, ARB's Old Man Emu MT64. The MT64 is the new kid in that lineup, but it is absolutely not a "starter" shock. It is a deeply engineered, monotube, aerospace-aluminum-bodied performance shock that competes head-on with the best non-reservoir options on the market and, depending on what you actually do with your truck, beats most of them. Let's get into why.

What Is the ARB MT64?
The MT64 is a monotube performance shock built by ARB's Old Man Emu (OME) suspension division. It sits above the long-running OME Nitrocharger line and below the fully-adjustable, premium BP-51. Think of it as ARB's answer to a very specific question: how do you build a shock that rides better than 90% of what's on the market, handles real loads, survives genuinely abusive terrain, and never asks the owner to think about damping settings? The answer is a 2.8" outer body, 2.5" (64mm) internal piston bore, large-displacement monotube architecture with a generous oil capacity, sophisticated piston and shim tuning, and a clever circlip-adjustable spring seat that lets a single shock platform serve a wide range of payload and ride-height needs.

You'll see the MT64 referred to as a "shock," a "strut," and a "coilover" depending on the application. On solid rear axles (Tacoma, Tundra, F-150), the rear MT64 is a traditional shock used with a matched OME coil or leaf pack. On the front IFS of these trucks, the MT64 is supplied as a ready-to-bolt-in strut assembly with a spring already pre-loaded, which is functionally a coilover. Same shock body, same internals, different presentation per axle.

Why "MT64" Means Something
The naming is not marketing fluff. Pull it apart: MT means Monotube, and 64 is the 64mm internal piston bore (2.5 inches). That tells you almost everything about the design intent. Monotube means a single body with a free-floating piston dividing oil and gas, which gives faster heat dissipation, more consistent damping under repeated abuse, and more usable internal volume than a twin tube. The 64mm bore means a piston roughly the size of a Fox 2.5 or Bilstein 8112, and considerably larger than the 46mm piston in a typical Bilstein 5100 or factory shock. Larger bore equals more oil equals more heat capacity equals less fade on long, hot, washboard descents. It also lets engineers use bigger shim stacks, which are the actual "tuning" of the shock.

The MT64 is built in the same family as the BP-51, ARB's flagship adjustable shock, and uses the same aerospace-grade aluminum body, the same hard-anodized military-spec finish, and benefits from the same R&D pipeline. The trade-off versus BP-51 is simple: you give up external adjustability, and in exchange you get a more affordable, simpler, lighter, and lower-maintenance package that ARB has already tuned for the vehicle.

Every Spec, Explained
Specs sheets are useless without context, so here's every meaningful number on the MT64 and what it actually does for your truck.

2.8" body / 2.5" (64mm) internal bore. One of the largest monotubes available, period. More oil capacity, more heat capacity, room for bigger shim stacks and finer damping tuning.

22.5mm (7/8") hard-chrome piston rod. Most aftermarket performance shocks use a 5/8" (16mm) shaft. Going to 7/8" dramatically increases resistance to side-load and bending under hard impacts, which is when shocks fail catastrophically off-road. It also changes the displacement ratio inside the shock, allowing engineers to dial in a more progressive rebound damping curve.

Aerospace-grade aluminum body. Heat is the enemy of every shock. As oil heats up, viscosity drops, damping fades, and the truck starts to wallow over the same terrain that felt composed five minutes earlier. Aluminum sheds heat several times faster than steel, which keeps the oil in its designed operating range and damping consistent from the start of a trail to the end.

Military-spec hard-anodized finish. Excellent corrosion resistance, withstands extreme temperature swings, far more durable than paint or powder coat on a body that lives at high temps.

Velocity-sensitive damping (no external adjustment). ARB tuned the damping curve for the platform. No knobs to fuss with, no settings to second-guess.

Hydraulic end-zone top out. As the shock approaches full extension (the end of a droop event coming off a bump), an internal hydraulic feature progressively cushions the top-out instead of letting the shock slam into a hard stop. This translates directly into fewer jarring impacts in the cabin and longer life for mounts and bushings.

Six-position adjustable spring seat (5mm increments). Roughly an inch of total adjustment range, set via a snap ring on machined ridges in the strut body. More on this below.

Forged 6061 aluminum end caps. Stronger than cast, better at dissipating heat, no shortcuts.

Double-bonded rubber bushings. These are a quiet superpower. Polyurethane bushings (common on cheaper "performance" shocks) transmit far more noise and vibration into the cabin than rubber. ARB's bonded rubber gives the MT64 some of the best NVH manners in the entire performance segment.

Replaceable HDPE shaft guard. After enough trail miles, the polyethylene gets pitted by rocks and debris. Replace the guard, save the chrome shaft, save the seal pack, save the shock.

Multi-lip combo seal + integrated wiper bump cap. Built to survive high pressure, high shaft speed, and high temperature, while keeping mud and grit completely out of the seal pack.

3-year warranty + ARB's global support network. Strong for a non-adjustable performance shock, and backed by a manufacturer that has been in the business for over 50 years.

The Six-Position Adjustable Spring Seat (How It Actually Works)
This is the feature that gets misunderstood the most online, so let's make it simple. The MT64 strut body has six machined ridges. A heavy-duty snap ring (circlip) sits on one of those ridges and supports the lower spring seat. Move the snap ring up a ridge, and the spring seat rises 5mm, which preloads the spring more and effectively raises ride height. Move it down a ridge, and ride height drops 5mm. That gives 25mm (about 1 inch) of total adjustment range across the six positions.

Why this matters: most aftermarket lift kits assume an "average" build, which means if you bolt on bumpers, sliders, a winch, a roof rack with a tent, drawers, and a fridge, your front end sags below the kit's design height. With MT64, you can dial up the front to compensate without reordering springs. Important: this is not a damping adjustment. It changes ride height and spring preload only. It does require disassembling the strut to move (you're not turning a collar by hand on the truck). Plan to set it at install and revisit only when your accessory weight changes meaningfully.

2024+ Toyota Tacoma (4th Gen)
The 4th gen Tacoma launched on the substantially revised TNGA-F platform with a coil-sprung rear (on TRD Off-Road, TRD Pro, Trailhunter and similar trims) and significantly more curb weight than the previous generation. From the factory, even the Trailhunter and TRD Pro are tuned more for occasional dirt and showroom appeal than for sustained high-speed off-road work, and any meaningful accessory weight quickly overwhelms the OEM dampers.

What the MT64 does for a 4th gen Tacoma: restores composure with bumpers, sliders, a rooftop tent, drawers, and skids installed. Adds roughly 1.5 to 2 inches of usable lift at the front depending on spring choice and seat position. Levels rear sag from heavy bed loads (drawers, fuel cans, recovery gear). Significantly improves washboard and corrugation behavior, which the factory truck handles poorly. Lowers cabin noise on broken pavement thanks to the rubber bonded bushings. Who it's for: owners building real overland rigs, daily drivers who tow trailers or boats and want better composure, anyone who has installed weight and noticed the OEM ride degrade.

2022+ Toyota Tundra (3rd Gen)
The 3rd gen Tundra brought a new coil-sprung rear (a huge change from the leaf-sprung 2nd gen) and a rear air suspension option on certain trims. It also brought weight: even base trims push past 5,500 lbs, and Capstone and 1794 trims are heavier still. The OEM monotubes aren't bad, but they are tuned soft and they fade quickly under heat or load.

What the MT64 does for a 3rd gen Tundra: tames body roll with a roof rack, RTT, and full-size spare on the rear. Greatly improves towing composure, particularly on broken pavement at highway speed. Restores ride height when the rear coils sag from chronic loaded use. Eliminates the porpoising that some owners report on long highway sweepers. Adds front lift for 35" and select 37" tire fitments depending on overall build. Note for air-suspension Tundras: confirm fitment carefully. ARB does offer applications for these trims, but kit components differ. Don't assume parity with steel-spring trims.

2021-2024 Ford F-150 (14th Gen)
The 14th gen F-150 is the volume sales leader of the segment for a reason: it does almost everything well from the factory. But "well from the factory" still means tuning that is conservative for ride and not built for sustained dirt abuse, and it absolutely does not account for a winch bumper, skids, and a bed full of gear.

What the MT64 does for a 21-24 F-150: adds roughly 2 inches of usable front lift to clear 33" or 35" tires depending on wheel offset and trim. Restores rear ride height when the truck is consistently loaded with bed weight. Provides massive composure improvement on washboard and broken dirt. Reduces the "head toss" sensation factory F-150s exhibit on rough sweeping turns. Cuts highway porpoising on long-bed configurations. Important fitment notes: confirm engine variant (PowerBoost hybrid carries additional front-axle weight that can change spring rate selection), Raptor is a separate platform not covered by the standard MT64 F-150 kit, and Tremor trim has different factory tuning but is generally compatible with the standard 21-24 application.

MT64 vs Fox 2.5
This is the comparison most buyers care about, because Fox 2.5 has owned the "performance shock" mindshare in this segment for the better part of a decade. Both shocks share the 2.5" internal piston bore and aluminum body construction, but they aim at slightly different missions. The Fox 2.5 (especially with reservoirs and DSC adjusters) is faster in pure off-road performance terms, particularly at sustained speed in rough terrain. The MT64 is more refined on-road, quieter in the cabin, more livable as a daily, and substantially simpler to live with long term. The MT64 also runs a larger 7/8" shaft (Fox 2.5 standard is 5/8") and has the 6-position spring seat adjustment, which Fox does not. For 80% of customers buying a Tacoma, Tundra, or F-150 to use as a do-it-all rig, the MT64 is the better fit. For dedicated dirt drivers who push hard and aren't bothered by a slightly firmer street ride, Fox 2.5 with reservoirs still has the edge.

MT64 vs Bilstein 6112 / 8112
Bilstein's premium upgrade shocks are the closest direct competitor to the MT64 in spirit: high quality, no remote reservoirs, focus on ride and durability over external adjustability. The Bilstein 6112 is a tier below the MT64 in capability and is closer to a "premium daily driver" upgrade. The 8112, with its DSA digressive valving and aluminum body, is a much closer match. Bilstein's DSA tends to feel slightly more controlled under aggressive cornering, while the MT64's bigger internal volume and shim flexibility tends to feel slightly plusher and quieter in everyday driving. The MT64 also has the larger 22.5mm shaft, which gives it a small edge in raw durability under abusive terrain. Either is a strong choice; the MT64 leans toward refinement and load handling, the 8112 leans toward composed sportiness.

MT64 vs ICON 2.5
ICON's 2.5 series has loyal fans, particularly in the Toyota community, and it competes head-on with the MT64 on body size and bore. ICON's 2.5 is closer in spirit to Fox 2.5: it's a performance-first product that rewards tuning and is designed to be opened, rebuilt, and revalved. The MT64 is closer to a finished product that ARB has already tuned to the platform. If you enjoy the tinkering side of suspension and want to dial in your own valving over time, ICON is excellent. If you want a shock that performs at a high level out of the box and asks nothing of you afterward, the MT64 wins. The MT64 also has the larger shaft and the spring seat adjustment, which ICON's standard 2.5 does not.

MT64 vs OME BP-51 (Same Family, Very Different Mission)
The BP-51 is the flagship of the OME line. The temptation is to assume "more expensive equals better in every way." That's not how to think about it. BP-51 has an integrated reservoir and external compression and rebound adjusters. The MT64 has neither. If you want to genuinely change your damping for a tow weekend versus a trail weekend versus a road trip, BP-51 is the right tool. If you want one suspension tune that's correct year-round, the MT64 is purpose-built for that. Most customers should buy MT64. BP-51 is for the customer who actually wants to live on the adjusters, not the customer who just likes the idea of having them.

MT64 vs OME Nitrocharger (The Older OME Option)
The Nitrocharger is the long-running OME twin-tube. It is well-loved, proven, and substantially cheaper than the MT64. So why upgrade? Nitrocharger is a twin-tube; MT64 is a monotube. Heat dissipation favors the monotube significantly. Nitrocharger has a smaller piston and shim stack; MT64 can be tuned more precisely and feels more refined. Nitrocharger uses a steel body; MT64 uses aerospace aluminum. Nitrocharger has no spring seat adjustment; MT64 has six positions. The honest answer: the Nitrocharger is still a good shock for a budget-conscious overland build, particularly on older trucks. For 2021+ F-150, 2022+ Tundra, and 2024+ Tacoma owners running modern truck weights with modern accessory loads, the MT64 is the right choice.

Ride Quality, Real World Expectations
Setting expectations is half of customer satisfaction with any premium shock, so here's the unvarnished version.

On smooth highway: noticeably plusher than factory. Highway expansion joints feel softened, not crashed-over. Long sweeping curves feel more planted, less floaty. The first 200 miles after install will feel slightly firm; the bushings settle and the dampers fully heat-cycle in this window.

On broken pavement: this is where the MT64 makes converts. The combination of the rubber-bonded bushings and the larger oil capacity makes secondary impacts (the small jolt after the big bump) almost disappear. Cabin noise drops. Steering feels tighter because the front end isn't busy resetting itself after every imperfection.

On washboard / corrugations: the MT64's monotube design and large shim stack let it cycle fast without fading. Where the factory shocks would start floating you over the surface after 30 seconds, the MT64 stays composed. This is one of the biggest differentiators versus OEM and budget shocks.

Under load (towing or bed weight): with the spring seat dialed appropriately, sag is reduced and the rear stays controlled. Trailer sway recovery is faster because the suspension settles between inputs rather than carrying motion forward.

Off-road, moderate pace: excellent. Compliant on small-to-medium hits, well-controlled on bigger compressions, and the hydraulic top-out keeps droop events from kicking the cabin.

Off-road, hard pace (sustained whoops, jumps): good for a non-reservoir shock, but this is where a 3.0 reservoir setup starts to pull ahead. Heat and sustained shaft speed are the enemies, and a reservoir adds oil volume specifically to handle that.

Installation, Break-In, and Configuration Tips
A few things make the difference between a good install and a great one. Fully torque to spec at ride height: lower control arm bushings should be torqued with the suspension loaded, not at full droop on a lift. This is the single biggest source of premature bushing wear on aftermarket suspensions. Set spring seat position before install: it is dramatically easier to set the snap ring when the strut is on the bench than when it's bolted into the truck. Decide on your accessory load and choose your position upfront. Plan for 200 to 500 miles of break-in: the shock will feel slightly firm and the bushings slightly stiff for the first few hundred miles. Wait until break-in is complete before evaluating ride quality. Always get an alignment after any ride-height change of more than half an inch. Re-check torque after 500 miles because suspension fasteners settle.

Pricing and Kit Strategy
The MT64 sits in the upper-middle of the suspension market. It is more expensive than Bilstein 5100 or OME Nitrocharger, roughly comparable to Fox 2.0 and ICON 2.0, and below Fox 2.5 with reservoirs, ICON 2.5 with reservoirs, and BP-51. The right way to buy MT64 is as a complete kit: front struts (or front shocks plus springs depending on platform), rear shocks, and matched springs front and rear. Mixing and matching MT64 with mismatched springs from another brand defeats the engineering work ARB did to tune the package. Buy the kit.

We package MT64 as part of our complete suspension solutions for Tacoma, Tundra, and F-150, with the right spring rate selected for your accessory weight and your intended use. If you tell us how you're building the truck (daily, tow, overland, weight on the front, weight in the bed), we'll get you the right configuration the first time. No guesswork, no second orders.

Final Verdict
The ARB Old Man Emu MT64 is, in our view, the most refined non-reservoir performance shock available for the 2024+ Toyota Tacoma, 2022+ Toyota Tundra, and 2021-2024 Ford F-150 right now. It nails the brief that most modern truck owners actually have, which is "I want my truck to ride better, handle weight, and survive real off-road use, but I don't want to live on adjusters and I don't want to babysit the shocks." For Tacoma owners building overland rigs, the MT64 is the strongest single platform we'd recommend. For Tundra owners towing or carrying weight, the MT64 transforms the truck into a noticeably better long-distance machine. For F-150 owners who want a real upgrade over the FX4 and Tremor experience without giving up daily livability, the MT64 is the right tier. If your build mission is high-speed desert or pure trail-tinkering, look elsewhere. For everyone else who wants the best do-everything shock available right now, this is it.