Planning a service kit for a 4S Arrma? The good news: you don’t need a separate bottle of everything for every truck. The key is to choose the right shared consumables, then check the model-specific parts against your manual or exploded view. Every shop link below goes to an AT Models product page; check the page for current availability before ordering.
Key Takeaways
- The 4S Arrma range covered here includes the Kraton 4S V2, Outcast 4S V2, Mojave 4S BLX and Quake 4S.
- These cars share some 4S drivetrain parts and consumables, but not every component fits every model.
- The main wear checks are differentials, shocks, bearings, driveshafts and tyres.
- Buy oil weights only when the product name states them; for factory fills and quantities, check your manual.
- Add silicone grease and blue threadlock to your service supplies, using each only where appropriate.
Regular inspection is what keeps a fast car feeling predictable. For when to inspect and service, see our RC Maintenance 101 guide. And if you’re still weighing up power classes, our Arrma 4S overview is a useful starting point.
Arrma Kraton 4S V2 BLX
Start with the car’s differentials: the geared units that distribute drive to the wheels and help them turn at different speeds through a corner. A leaking seal, rough bearing or damaged gear can quickly turn a routine run into a drivetrain repair. Check the exact assembly in the exploded view before ordering: similar-looking diff sets can have different gear counts or applications.
- Diff service: Diff Maintenance Set, 29mm diff gear set and 29mm diff shim set.
- Replacement diff assemblies: the 43T spiral front/rear set is labelled with 10k oil; the 50T centre diff set is labelled with 100k oil. Match the product’s gear specification to your manual before buying. These printed oil weights are product-specific, not a claim about every Kraton’s factory fill.
- Shocks: Shock Seal Guide Set and shock bladders are useful service parts. For oil, the product names identify Fastrax 30wt and 35wt. wt is the oil’s weight grade; choose to match your setup or manual.
- Bearings: check sizes and locations against the parts diagram. The guide’s listed options include 8×16×5mm, 6×10×3mm and 15×21×4mm. The RPM Bearing Blaster helps clean serviceable bearings.
- Workshop essentials and wear parts: silicone grease helps protect suitable seals and contact points; ZAP PT42 blue threadlock helps keep appropriate metal-to-metal fixings secure under vibration. Check the manual before applying either. For model-specific parts, use the Kraton 4S V2 spares hub or the Kraton 4S spares hub. The 57T metal centre diff set is listed for the 4S family. For tyres, check the fitment on Copperhead2 LP 3.8-inch tyres. 1/10 body clip retainers are handy spares.
Pro tip: 4S torque can work wheel hexes loose or wear their drive faces. Check for rounded hexes after hard bashing before they damage the wheel.
Quick answers
- Which diff oil should I use? Follow the manual for the exact diff and fill. The linked diff-set names state 10k or 100k for those specific assemblies.
- How often should I change shock oil? Follow your manual and check for leaks or inconsistent damping; usage and conditions affect service needs.
- Which bearings should I check first? Inspect for grit, roughness or play, especially after dusty or wet running. Confirm each replacement size against the diagram.
Arrma Outcast 4S V2 BLX stunt truck
The Outcast shares much of its 4S drivetrain family with the Kraton, so use the Kraton section for the general diff, bearing and service consumable checklist. The difference is how it lands: repeated jumps and stunt impacts put extra stress on shock shafts and body mounts. Inspect those after heavy sessions rather than waiting for a bent shaft to affect suspension movement.
- Model-specific hubs: Outcast 4S V2 spares and Outcast 4S spares.
- Impact-prone items: check shock shafts for bends and body mounts for cracks. The body mount set is listed for the Kraton and Outcast 4S V2. For replacement shafts, match the dimensions and part number shown in your exploded view; the 4Ă—62mm shaft pair is listed in the Kraton 4S V2 spares selection. Keep body clips and pads on hand where the diagram confirms fitment.
Pro tip: Keep a couple of the correct body clips in your toolbox. A lost clip is a small part, but it can sideline a session.
Quick answers
- What should I inspect after a jump session? Look for bent shafts, cracked mounts, loose fasteners and damage around the body posts.
- Can I use the Kraton’s service list? Use it as a starting point for shared consumables, then verify every part number against the Outcast diagram.
Arrma Mojave 4S BLX desert truck
The Mojave brings the 4S drivetrain into a 1/8-scale chassis. That means the oil-selection approach is familiar, but the car’s scale and layout make it especially important to check the exact part number, fill quantity and wheel fitment in its manual. Don’t assume a Kraton part fits simply because both cars are 4S.
- Parts hub: Mojave 4S spares.
- Drive and rolling wear: inspect dogbones, CVDs and their cups for wear or damage; confirm the diagram before replacing. The 135mm dogbone is listed as fitting the Mojave 4S. For tyres, the dBoots Fortress LP 17mm-hex set is listed for this model.
- Small but useful spares: 1/8 body clip retainers suit the larger shell scale. The body clip and pad set is also listed for Mojave 4S.
Quick answers
- Does the Mojave use the same oil approach as the other 4S cars? Yes: choose silicone oils by the manual’s specification, not by assuming every fill is shared.
- Why check fill quantities separately? The Mojave’s 1/8 chassis and individual assemblies dictate their own quantities; check the manual.
Arrma Quake 4S DSC monster truck
The Quake is a newer 4S brushless platform, so use the Kraton section for shared consumables such as suitable oils, seals and bearings, but confirm each size and fitment against the Quake exploded view. Its Quake 4S spares hub is the best place to start. Model-specific availability is still building, so the Parts Finder is a useful check before you order. Don’t rely on a part labelled simply “Quake” unless the listing confirms it fits the Quake 4S.
Quick answers
- Can I use Kraton 4S oils and bearings? Use the same general selection method, but confirm the Quake’s specified oil and bearing sizes first.
- Where do I find a Quake-specific replacement? Start with its spares hub or check the model in the Parts Finder.
Ready for your next service?
A well-chosen kit keeps routine maintenance simple and helps you spot wear before it becomes a bigger repair. Browse Arrma car spares or use the Parts Finder to confirm the exact part for your model. If you’re comparing 3S and 4S service needs, look for the companion Arrma 3S Service Kit Guide in the Arrma service-kit series.
Meta title: Arrma 4S Service Kit Guide | What to Buy Meta description: Oils, bearings, greases and wear parts for every 4S Arrma we stock. Kraton, Outcast, Mojave and Quake 4S service shopping lists, all live links. Tags: Arrma, Service Kit, 4S BLX, RC Maintenance, Hints & Tips Category: Cars
