Overview
The ARRMA Assembled Oil Filled Differential 30T 0.8Mod, 3000cSt Oil is a factory-assembled drivetrain replacement component designed specifically for ARRMA 1/16 and 1/18 scale RC monster trucks, including the GROM, GRANITE GROM, QUAKE GROM, and GORGON GROM models. This oil-filled differential comes pre-assembled and pre-filled, making it an ideal solution for RC enthusiasts in the UK who need a fast and efficient upgrade or replacement part for their brushed 4WD RC vehicles. Whether you're a weekend basher enjoying outdoor RC car fun or someone looking to maintain their existing monster truck in peak condition, this differential represents genuine ARRMA quality and engineering at an accessible price point.
Oil-filled differentials are essential components in any RC car or monster truck, as they manage power distribution between the left and right wheels, enabling smooth cornering and improved traction across a variety of terrain. The factory assembly means you receive a fully ready-to-install component that eliminates the complexity of building your own differential from scratch. This is particularly valuable for RC model enthusiasts who want to spend more time driving and less time on assembly, or for those replacing a worn or damaged differential who want guaranteed compatibility and performance from day one.
ARRMA has engineered this differential with durability and reliability at its core, making it a trusted choice for RC enthusiasts across the UK and beyond. The pre-filled silicone oil ensures consistent performance characteristics, eliminating guesswork about oil viscosity and compatibility. This differential is a genuine OEM replacement part, meaning it meets ARRMA's exacting standards for fit, function, and longevity under the demanding conditions of RC off-road driving.
Key Features
- Factory Assembled and Pre-Filled — This differential arrives completely assembled with 3000 cSt silicone oil already inside, eliminating the need for time-consuming manual assembly or oil filling. This means you can install it straight from the box and get back to driving your RC monster truck within minutes, which is perfect for busy RC enthusiasts who want convenience without compromising on quality.
- 30T 0.8 Modulus Main Diff Gears — The 30-tooth gears with 0.8 modulus specification deliver increased durability under extreme loads and aggressive driving conditions. This tooth count and modulus rating ensure that your ARRMA RC vehicle can handle bashful impacts, high-speed runs, and challenging off-road terrain without gear slippage or premature wear, making it suitable for both casual and competitive RC driving.
- Tough Internal Gears for Long-Lasting Durability — ARRMA engineers these internal gears to withstand the punishment of serious RC driving in all conditions, from smooth tarmac to rough grass, mud, and gravel. The robust construction means fewer replacements over time, saving you money and keeping your RC car on the track or field rather than in the workshop.
- Includes Bearings — The differential comes complete with all necessary bearings installed, enabling fast and efficient fitting to your vehicle. You won't need to source additional bearings separately or spend time matching components, as everything required for installation is included, streamlining the upgrade or replacement process.
- 3000cSt Silicone Oil — The pre-filled 3000 centiStoke silicone oil provides optimal viscosity for smooth differential action and reliable performance across the temperature ranges typical of UK RC driving. This oil viscosity ensures proper fluid film between gear teeth whilst maintaining the responsiveness that drivers expect from modern RC monster trucks.
- Genuine ARRMA Component — This is an authentic ARRMA parts component, not an aftermarket copy, meaning it's guaranteed to fit your GROM, GRANITE GROM, QUAKE GROM, or GORGON GROM without modification and to perform exactly as the manufacturer intended.
Technical Performance
This assembled differential represents ARRMA's commitment to engineering robust drivetrain components for their 1/16 and 1/18 scale RC monster trucks. The 30-tooth 0.8-modulus gear specification balances acceleration, top-end speed, and torque delivery, making it suitable for a broad range of driving styles and terrain conditions. The 3000 cSt silicone oil provides the ideal balance between smooth, progressive differential action and sufficient viscosity to prevent gear chatter under load. Internal gears are manufactured to tight tolerances, and the complete bearing set ensures that rotational forces are distributed smoothly across multiple contact points, reducing wear and extending the service life of your RC vehicle's drivetrain. The factory-assembled design means that all components are matched and tested before leaving ARRMA's facilities, guaranteeing that when you install this differential, it will perform consistently and reliably. This is a critical advantage over building your own differential, as even small variations in assembly technique can affect performance characteristics. For UK RC enthusiasts driving ARRMA GROM-series trucks, this differential is engineered to handle the demands of bashful driving, speed runs, and technical obstacle courses with equal proficiency.
What's in the Box
- ARRMA Assembled Oil Filled Differential 30T 0.8Mod with 3000cSt silicone oil
- Pre-installed bearings
Frequently Asked Questions
- Is this oil-filled differential suitable for beginners in the RC hobby? — Yes, absolutely. This product is perfect for beginners because it arrives completely pre-assembled and pre-filled with the correct oil viscosity. You don't need any technical knowledge to install it; it simply bolts into your ARRMA GROM-series truck and works immediately. This makes it ideal for newcomers to the RC hobby who want to maintain or upgrade their vehicle without worrying about complex differential assembly procedures.
- What ARRMA models are compatible with this differential? — This differential is specifically designed for 1/16 and 1/18 scale ARRMA GROM-series models, including the GORGON GROM 4X4 (all colour variants), GRANITE GROM MEGA 380 Brushed 4X4 (all colour variants), and QUAKE GROM 4X4 (all colour variants). Always verify your specific model number before ordering to ensure compatibility.
- Why is 3000cSt oil the right viscosity for my RC monster truck? — Silicone oil viscosity directly affects how quickly your differential responds to changes in traction and load. 3000 cSt oil provides a middle ground that works well across a variety of UK driving conditions—it's fluid enough to prevent lag during fast cornering but viscous enough to provide smooth, controlled power distribution during acceleration and off-road driving. This viscosity is ARRMA's factory standard for these models, meaning it's been tested and proven in the field.
- Do I need to add oil to this differential myself? — No. This is one of the key advantages of choosing a factory-assembled, pre-filled differential. The 3000 cSt silicone oil is already inside and at the correct level, ready to perform. You simply install the differential onto your RC truck and start driving. This eliminates the risk of overfilling or underfilling, both of which can cause performance problems.
- How long will this differential last before needing replacement? — With proper maintenance, including regular checks for oil leaks and general cleanliness, this differential should provide years of reliable service. The tough internal gears and robust bearing construction mean it can handle hundreds of hours of driving. However, if you drive in particularly muddy or wet conditions frequently, you should check for water ingress periodically, as moisture can degrade silicone oil performance over time.
- Can I use this differential as an upgrade to my existing GROM? — Yes. If your current differential is worn, damaged, or simply underperforming, this replacement will upgrade your truck's drivetrain characteristics. The 30T 0.8Mod gears offer excellent durability and balanced performance, making this a direct improvement over many factory-original differentials in older GROM models.
Why Buy from RC Model Shop?
RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the ARRMA Assembled Oil Filled Differential 30T 0.8Mod, 3000cSt Oil: G Z-ARA-3067 today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.
We want to make sure your delivery goes smoothly, so here are some important details about our service:
- For orders above £120, we offer delivery to most mainland UK addresses. For orders under £120, we can still deliver to Northern Ireland and the outlying isles, as long as the item can be sent by Royal Mail, weighs less than 30kg, and fits within 61cm × 46cm × 46cm. Some highland and remote areas may carry an extra delivery charge as couriers often apply surcharges in these locations. If you live in one of these areas, feel free to contact us before ordering so we can confirm the delivery options and costs for you.
- Most of our products include delivery in the price. If your order is under £90, a small delivery fee will apply but do not worry this will always be clearly shown at checkout before you complete your purchase.
- Depending on what you choose at checkout, your order will usually be delivered either the next working day or within 2 working days. For next day delivery please place your order before 2:00pm. Orders are dispatched Monday to Friday only. Some items may take a little longer and if that is the case we will always show the expected delivery time on the product page.
- If your order includes items with different dispatch times we will normally wait and send everything together once all items are in stock. If one of the items is going to take a while we will give you the choice either wait for everything to arrive or let us send the available items now and deliver the rest later. It is up to you.
- We use trusted delivery partners to make sure your order gets to you safely and on time. We use DPD for next working day deliveries and Royal Mail for the 2 day option.
- As soon as your order is on its way we will send you a tracking number by email. If you provide your mobile number at checkout we will also send delivery updates straight to your phone so you can keep an eye on progress.
- If a product is marked as "Dispatched within 3 working days" delivery usually takes around 3 to 5 working days from when your order is placed.
- For customers in Inverness and other parts of the Scottish Highlands deliveries can take up to 2 working days even if you select next day delivery as couriers do not currently offer a guaranteed next day service to those areas.
