Upgrades
The best Traxxas Slash upgrades
There is a right order to this, and it is not the exciting one. Strengthen what breaks, improve what you feel, and only then add power — which is precisely what Traxxas' own upgrade guide says.
By Ryder M. · Published September 29, 2026 · Last reviewed
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The Slash 4X4 is the most upgraded RC car in the world, which means there is no shortage of parts and a great deal of bad advice about which to buy first. Traxxas publishes its own three-phase upgrade path — suspension, then shocks and steering, then brushless power — and it is right. Start with heavy-duty suspension arms.
In order: stronger arms so it stops breaking, a high-torque servo so it steers, GTR shocks so it lands, a second LiPo so it runs twice as long, and only then the brushless system. Power last, always.
Buy this first
Traxxas Heavy-Duty Suspension Arms
The stronger factory A-arms, part 3655T. The cheapest upgrade that actually prevents a repair.
Biggest felt difference
Traxxas High-Torque 330 Coreless Servo
330 ounce-inches of steering torque against the stock servo's 80. The upgrade people notice within one run.
Best before any of it
Traxxas GTR Long Aluminum Shocks
Aluminum-bodied oil shocks with 70% more oil capacity than the standard ones, which is what stops them fading.
Why power goes last
Every component downstream of the motor is sized for the power the truck left the factory with. Double that power and the driveshafts, the differential gears and the suspension arms all start failing at a rate they never did before. Fitting the brushless system to a standard chassis is how people end up with a very fast truck that spends most of its life in pieces.
The upgrades, in order
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 | Traxxas Heavy-Duty Suspension ArmsThe stronger factory A-arms, part 3655T. The cheapest upgrade that actually prevents a repair. | The part that breaks | 8.6 | |
| 2 | Traxxas High-Torque 330 Coreless Servo330 ounce-inches of steering torque against the stock servo's 80. The upgrade people notice within one run. | Steering that responds | 8.8 | |
| 3 | Traxxas GTR Long Aluminum ShocksAluminum-bodied oil shocks with 70% more oil capacity than the standard ones, which is what stops them fading. | Landing jumps | 8.5 | |
| 4 |  Traxxas Power Cell 2S LiPo batteryThe no-thinking-required upgrade if the car in question is a Traxxas. | Traxxas owners | 8.6 | |
| 5 |  Traxxas Velineon VXL-3s Power SystemThe motor-and-speed-control kit that turns a brushed Slash into a 60+ mph one. Fit it last, not first. | Brushed to brushless | 8.4 | |
| 6 | Traxxas Aluminum Center DriveshaftThe extruded aluminum shaft that replaces the composite one, because the composite one is what gives way under brushless power. | After going brushless | 8.2 | |
| 7 |  Traxxas EZ-Peak chargerThe charger Traxxas itself recommends for its cars, and the one that needs no settings at all. | Traxxas households | 8.5 |
Illustrative photo — not this exact model.
#1 · The part that breaks
Traxxas Heavy-Duty Suspension Arms
The stronger factory A-arms, part 3655T. The cheapest upgrade that actually prevents a repair.
8.6/10our score for this use
Suspension arms are the wishbone-shaped links between the chassis and the wheels, and they are what snaps when a truck lands badly or catches a curb. Traxxas sells a heavy-duty version molded in a stronger plastic, listed as phase one of its own published Slash 4X4 upgrade path.
What it does well
- Named in the manufacturer's own three-phase upgrade guide, so fitment is not a gamble
- Plastic that flexes and returns beats aluminum that bends and stays bent
- Cheap enough to buy a spare set at the same time
What it does badly
- It is a durability part, not a performance one — nothing about the truck gets faster
- You need the correct set for your exact Slash version
- Fitting them means taking the suspension apart, which is a first-timer's afternoon
Specifications from the Traxxas Slash 4X4 upgrade guide.
Illustrative photo — not this exact model.
#2 · Steering that responds
Traxxas High-Torque 330 Coreless Servo
330 ounce-inches of steering torque against the stock servo's 80. The upgrade people notice within one run.
8.8/10our score for this use
The servo is the small motor that turns the front wheels. The unit fitted to a standard Slash has plastic gears and 80 ounce-inches of torque, and in deep grass or against a curb it simply gives up. Traxxas lists the 2250 coreless servo at 330 ounce-inches as the phase-two answer.
What it does well
- Four times the steering torque, which is the difference between turning in wet grass and ploughing straight on
- Metal gears, so an impact through the front wheels does not strip it
- Plugs into the existing receiver — no soldering
What it does badly
- Expensive next to the plastic-geared servos it replaces
- Stronger steering loads the steering linkage, which becomes the next thing to break
- Almost no benefit if the truck only ever runs on smooth ground
Specifications from the Traxxas Slash 4X4 upgrade guide.
Illustrative photo — not this exact model.
#3 · Landing jumps
Traxxas GTR Long Aluminum Shocks
Aluminum-bodied oil shocks with 70% more oil capacity than the standard ones, which is what stops them fading.
8.5/10our score for this use
Shock absorbers control how the suspension moves. The standard plastic-bodied shocks hold little oil, so after a few minutes of hard driving the oil heats, thins and the truck starts bottoming out. Traxxas' GTR shocks are aluminum with titanium-coated shafts and, by the company's own figure, 70% greater oil capacity.
What it does well
- Consistent damping through a whole battery pack rather than just the first three minutes
- Rebuildable: you replace the oil and seals rather than the whole shock
- Springs are sold separately, so the truck can be tuned for how it is actually driven
What it does badly
- Sold in pairs, so a full set is two purchases
- Only worth the money if the truck is genuinely being jumped
- Rebuilding shocks is fiddly and easy to get wrong the first time
Specifications from the Traxxas Slash 4X4 upgrade guide.
Illustrative photo — not this exact model.
#4 · Traxxas owners
Traxxas Power Cell 2S LiPo battery
The no-thinking-required upgrade if the car in question is a Traxxas.
8.6/10our score for this use
Traxxas' own LiPo packs carry an iD chip that tells a Traxxas charger exactly what the battery is, so there is nothing to set and nothing to get wrong. For a gift recipient who has never charged a LiPo, that matters more than a few percent of performance.
What it does well
- The iD system removes the single most intimidating part of LiPo ownership
- Fits Traxxas battery trays without adapters or foam packing
- Available at any shop that stocks Traxxas
What it does badly
- Costs more than an equivalent third-party pack
- The iD advantage only applies with a Traxxas charger
- Same LiPo storage rules apply — it still needs care
Specifications from Traxxas' batteries and chargers range.
Illustrative photo — not this exact model.
#5 · Brushed to brushless
Traxxas Velineon VXL-3s Power System
The motor-and-speed-control kit that turns a brushed Slash into a 60+ mph one. Fit it last, not first.
8.4/10our score for this use
A brushless motor has no carbon brushes to wear out, runs cooler and makes far more power. The VXL-3s is the complete factory conversion — motor, speed control and wiring — and Traxxas quotes 60+ mph performance from it.
What it does well
- Roughly doubles the performance of a brushed truck in a single purchase
- Includes Training Mode, so the extra power can be halved again for a younger driver
- No maintenance — there are no brushes to replace
What it does badly
- The most expensive item on this page by a wide margin
- Everything downstream breaks more often once power goes up. Do the suspension first
- A 60 mph truck needs open space that a 30 mph truck did not
Specifications from the Traxxas Slash 4X4 upgrade guide.
Illustrative photo — not this exact model.
#6 · After going brushless
Traxxas Aluminum Center Driveshaft
The extruded aluminum shaft that replaces the composite one, because the composite one is what gives way under brushless power.
8.2/10our score for this use
The center driveshaft carries power from the transmission to the axles. A standard Slash 4X4 uses a composite plastic shaft, which is fine behind a brushed motor and marginal behind a brushless one. Traxxas lists the aluminum shaft, plus the matching drive hub, in phase three of its upgrade path.
What it does well
- Directly addresses the part that starts failing once power goes up
- Cheap relative to the brushless system that creates the need for it
- The matching drive hub part number is published, so there is no guesswork
What it does badly
- Pointless on a brushed truck — the composite shaft is adequate at that power level
- Needs the separate drive hub to fit, which is a second purchase
- Metal transmits more driveline noise than plastic
Specifications from the Traxxas Slash 4X4 upgrade guide.
Illustrative photo — not this exact model.
#7 · Traxxas households
Traxxas EZ-Peak charger
The charger Traxxas itself recommends for its cars, and the one that needs no settings at all.
8.5/10our score for this use
Traxxas' own charger. With an iD-equipped Traxxas battery it detects the pack and sets itself, which removes the part of LiPo ownership that worries people most. It charges both NiMH and LiPo.
What it does well
- Automatic setup with Traxxas iD batteries — nothing to configure, nothing to get wrong
- Handles both the NiMH packs that come with entry cars and the LiPo upgrade later
- Stocked wherever Traxxas is sold
What it does badly
- The automatic behavior only applies to Traxxas iD packs
- Single channel, so packs charge one after another
- Costs more than a generic charger of similar output
Specifications from Traxxas' batteries and chargers range.
The three phases, summarized
| Phase | What you fit | What changes |
|---|---|---|
| 1 — Durability | Heavy-duty suspension arms | It stops breaking on landings and curb strikes |
| 2 — Control | High-torque servo and GTR shocks | It turns in grass and settles after a jump |
| 3 — Power | Brushless system, then the aluminum driveshaft | 60+ mph, and a driveline strong enough to take it |
| Any time | A second LiPo and a proper charger | Twice the driving per trip, and faster turnaround |
The one upgrade that is worth buying before any part on this list is a second battery. Nothing else on this page changes an afternoon as much as doubling the run time, and our battery and charger guides cover what to buy.
What not to bother with
- Oversized tires, until the rest of the truck is up to the extra load they put through the driveline.
- Anodized cosmetic parts. They change nothing, and they are usually heavier than what they replace.
- A bigger motor before better shocks. More speed into a suspension that is already bottoming out makes the truck worse, not faster.
How we picked
We follow the manufacturer's own published upgrade sequence and prioritize the parts that address a documented failure point over the ones that add performance. Every part named here appears in Traxxas' own guide, linked below. See our methodology.