Losi 1/12 NASCAR AWD Bearing Placement Guide: Sizes, Counts & Locations
Share
Losi 1/12 NASCAR AWD Bearing Placement Guide: Sizes, Counts & Locations
The Losi 1/12 NASCAR AWD racecar uses two bearing sizes in its wheel hubs and drivetrain. This guide covers the stock brushed NASCAR AWD platform shown in Losi’s LOS11225XX owner’s manual, with the factory ARA311177V2 front and rear differential assemblies. The FastEddy Bearings Losi 1/12 NASCAR AWD Sealed Bearing Kit (TFE9450) contains 16 bearings: eleven 7 × 11 × 3 mm and five 8 × 12 × 3.5 mm.
Dimensions are inside diameter × outside diameter × width, in millimeters. The quantities below are installed vehicle totals, not the quantities sold in factory replacement-parts packs.
Losi NASCAR AWD bearing placement table
| Assembly / location | Bearing size (ID × OD × width) | Quantity | Factory bearing reference |
|---|---|---|---|
| Front wheel hubs — two per wheel | 7 × 11 × 3 mm | 4 | ARA610053 |
| Rear wheel hubs — two per wheel | 7 × 11 × 3 mm | 4 | ARA610053 |
| Front differential input pinion shaft — two supports | 7 × 11 × 3 mm | 2 | ARA610053 |
| Rear input / spur-gear shaft — smaller support | 7 × 11 × 3 mm | 1 | ARA610053 |
| Rear input / spur-gear shaft — larger support | 8 × 12 × 3.5 mm | 1 | ARA610052 |
| Front differential carrier — one on each side | 8 × 12 × 3.5 mm | 2 | ARA610052 |
| Rear differential carrier — one on each side | 8 × 12 × 3.5 mm | 2 | ARA610052 |
Complete FastEddy Bearings Losi 1/12 NASCAR AWD Sealed Bearing Kit (TFE9450) size totals
- 11 × 7 × 11 × 3 mm
- 5 × 8 × 12 × 3.5 mm
Wheel hubs: eight 7 × 11 × 3 mm bearings
Each of the four wheel hubs uses two 7 × 11 × 3 mm bearings. The front pair of hubs accounts for four bearings, and the rear pair accounts for another four. Keep the wheel hexes, axle hardware and drive components organized as you remove them. Clean the hub seats and check the axles for damage before replacing the bearings.
Front input pinion: two 7 × 11 × 3 mm bearings
The front input shaft is supported by two 7 × 11 × 3 mm bearings. These are input-pinion supports, separate from the bearings on the differential carrier itself. Use the chassis exploded drawing to preserve the gear, shaft and hardware order.
Rear input and spur shaft: a mixed-size pair
The rear input / spur-gear shaft uses one 7 × 11 × 3 mm bearing and one 8 × 12 × 3.5 mm bearing. Do not install two matching bearings here just because both wheel bearings are the same size. Compare the shaft’s two seats with the chassis drawing; the larger support is identified as ARA610052 and the smaller support as ARA610053.
Front and rear differentials: four 8 × 12 × 3.5 mm bearings
The front differential carrier uses two 8 × 12 × 3.5 mm bearings, and the rear carrier uses two more. These sit on the external carrier journals, one at each side of each differential. They are not bearings inside the differential gear assembly. Retain the original assembly orientation and check for smooth rotation after closing each housing.
Installation and maintenance checklist
- Disconnect the battery before working. Photograph each assembly and keep its screws, spacers and shims together.
- Clean the bearing pockets and shafts before fitting replacements. A bearing should sit squarely and fully in its seat.
- Support the appropriate bearing race during installation. Avoid forcing a bearing into place or driving installation loads through the balls.
- Reassemble using the manufacturer’s drawings. Check each assembly for smooth movement before moving to the next one.
- After dusty or wet runs, wipe away dirt and dry the vehicle. Replace bearings that feel gritty, bind, develop excessive play or show corrosion. Rubber seals help keep debris out, but they do not eliminate maintenance.
Model and upgrade notes
Match the chassis and factory parts to the LOS11225XX documentation before ordering or installing bearings. Body number and livery alone do not identify an upgraded drivetrain. Aftermarket hubs or differentials can change the required fit. This guide does not assign replacement bearings to the motor or steering servo.
Manufacturer manuals and exploded views
-
Losi LOS11225XX English owner’s manual — see the parts list and Chassis and Suspension exploded views; the parts list identifies ARA610053 as 7 × 11 × 3 mm and ARA610052 as 8 × 12 × 3.5 mm.
Frequently asked questions
How many bearings are in the FastEddy Bearings Losi 1/12 NASCAR AWD Sealed Bearing Kit (TFE9450)?
The kit contains 16 bearings: eleven 7 × 11 × 3 mm and five 8 × 12 × 3.5 mm.
Are all sixteen bearings installed at the wheels?
No. Eight are wheel-hub bearings. The other eight support the front input shaft, rear input / spur shaft, and front and rear differential carriers.
What size bearings fit the wheel hubs?
Each wheel hub uses two 7 × 11 × 3 mm bearings, giving eight across the complete vehicle.
Where does the fifth 8 × 12 × 3.5 mm bearing go?
Four support the two differential carriers. The fifth supports the rear input / spur-gear shaft.
Can I use this table for a modified car?
Check the installed components first. If a hub, differential or shaft assembly has been changed, use its maker’s bearing specification and measure the existing bearing before selecting a replacement.
Service the factory bearing locations with the FastEddy Bearings Losi 1/12 NASCAR AWD Sealed Bearing Kit (TFE9450). Use the individual size links in the table when you need replacement-bearing packs.