Mazda CX-4,CX-5,CX-8, And CX-9 AWD Rear Differential Bearing Kit F-615360 F-611420.02 F-615438

Product Overview

The F-615360 / F-611420.02 / F-615438 kit is a rear differential bearing set for Mazda CX-4, CX-5, CX-8, and CX-9 AWD models. The kit contains the bearings required to service the rear differential carrier and pinion positions, addressing the bearing wear that produces whine, howl, or vibration from the rear axle. The three part numbers cross to Mazda OEM references KA03-27-350, KA03-27-210, and KA03-27-220 respectively.

Critical structural clarification: three bearing types, not a single uniform structure

The supplier form leaves Structure, Number of Rows, and all dimensional fields blank. Public data confirms the three part numbers are different bearing types and should not be described under a single structure heading:

• F-615360 (KA03-27-350): Angular contact ball bearing, 35 × 62 × 20 mm, nylon cage, open (no seals), GCr15 chrome steel, operating temperature range 150–200 °C. Mazda parts catalogues identify this as the Differential Carrier Bearing / Side Bearing for CX-5 AWD and CX-9.

• F-611420.02 (KA03-27-210): Catalogue entries are inconsistent on the exact bearing type. One source describes it as a tapered roller bearing (35 × 76 × 25 mm, steel cage), while another describes the same part number as a double-row radial ball bearing (76 × 35 × 25/22 mm). Mazda catalogues identify it as the Rear Pinion Bearing (Rear Inner) — the large pinion bearing that carries the primary radial and axial loads from the drive gear. The supplier must confirm whether the stock is the tapered roller or double-row ball variant before publication.

• F-615438 (KA03-27-220): Angular contact ball bearing, 30 × 55 × 17 mm (overall height; B = 13 mm for the inner ring), nylon cage, GCr15 chrome steel; weight ≈ 0.15 kg. Some catalogue entries cite an overall height of 16.95 mm, which is consistent with the 17 mm figure within measurement rounding. Mazda catalogues identify this as the Front Pinion Bearing (Rear Outer) — the smaller pinion bearing.

Critical dimensional correction: the keyword for F-615438 is inaccurate

The supplier form’s Keyword 3 states “F-615438 30x55x13/17mm.” The catalogue data confirms the bearing is 30 mm bore × 55 mm OD × 17 mm overall height, with 13 mm being the inner ring width (B) rather than a stepped total width. The 17 mm figure is the relevant overall mounting dimension for the listing; the keyword should be corrected to avoid fitment confusion.

Weight clarification

The supplier form lists 1.02 kg for the kit. Published individual bearing weights are ≈ 0.15 kg for F-615438 and ≈ 0.5 kg for F-611420.02 (KA03-27-210) in the double-row ball variant. The F-615360 weight is not explicitly published in the accessible sources, but a 1.02 kg combined kit weight is plausible when the three bearings are summed with packaging. The listing should clarify that 1.02 kg is a kit reference weight, not the mass of a single bearing.

Key Specifications

Performance Features

• Complete rear differential service set: The kit groups the carrier side bearing (F-615360) with the large pinion bearing (F-611420.02) and the small pinion bearing (F-615438), providing the bearings needed for a comprehensive rear differential bearing replacement on CX-4/CX-5/CX-8/CX-9 AWD models.

• Position-specific load management: The F-611420.02 is the rear inner pinion bearing, carrying the primary radial and axial loads from the drive gear. The F-615438 is the rear outer (front) pinion bearing, supporting the nose of the pinion shaft. The F-615360 is the differential carrier side bearing, positioning the carrier and managing the loads from the ring gear.

• Angular contact ball bearings (F-615360, F-615438): These manage combined radial and thrust loads at the carrier and pinion nose positions, with nylon cages providing low-friction ball guidance in the oil-lubricated differential environment.

• Tapered roller construction (F-611420.02, if applicable): The steel-caged tapered roller variant of the large pinion bearing provides high radial and one-direction thrust capacity for the primary pinion load path.

• Open, gear-oil-lubricated design: All bearings are supplied without integral seals, relying on the rear differential’s gear oil for lubrication and cooling.

• GCr15 chrome steel: Rings and rolling elements are produced from through-hardened chrome steel, providing rolling-contact fatigue resistance for differential service.

Application

The kit is specified for the rear differential of Mazda CX-4, CX-5, CX-8, and CX-9 AWD models. Published kit references explicitly list the F-615360, F-611420.02, and F-615438 combination for the rear axle reducer of Mazda CX-4, CX-5, CX-8, and CX-9. In service, the pinion bearings (F-611420.02 and F-615438) support the pinion shaft under the combined loads of the hypoid mesh, while the F-615360 carrier bearings position the differential carrier and resist the radial and thrust loads from the ring gear. Rear differential bearing failure typically presents as a whine, howl, or vibration that increases with road speed; rebuilding with a complete bearing kit is the recommended repair. Replacement requires differential disassembly and should follow Mazda’s procedure for pinion bearing preload, carrier bearing preload, and backlash adjustment. Some rebuild kits for this application also include oil seals and a crush sleeve; the listing should clarify whether these are included.

Ordering & Logistics

• Stock: 65 pcs (kit sets)

• Minimum order: 1 pc (kit)

• FOB price: US$100 – US$200 per kit

• Payment: PayPal / Western Union / T/T (100% in advance)

• Delivery: 3–4 workdays after payment

• Shipping: DHL / FedEx / UPS / TNT

• Ports: Shanghai / Guangzhou

• Packing: Standard export packing

• Brand: As required (authorized brands only)

• Country of origin: China

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