Powerflex Black 95A Polyurethane Rear Subframe/Cradle Mount Bush Inserts for BMW 4 Series F32 F33 F36 (Coupe, Convertible, Gran Coupe) | Rear Axle Carrier Bushing Void Filler Kit | Track Performance | PFR5-1921BLK | OE 33316792510 (Pair)

Powerflex Black Series rear axle carrier mount insert kit for BMW 4 Series F32 F33 F36

Part number: PFR5-1921BLK

Transform rear-end stability and precision with this track-focused rear axle cradle mount insert kit. Built in the Powerflex Black compound with a race-grade 95 Shore A hardness, these infill inserts occupy the voids in the factory rubber mounts to rein in unwanted subframe movement. The result is cleaner feedback, tighter response and repeatable geometry when driving hard on circuit or during aggressive road use.

We run these inserts on our own builds and customer cars, and the improvement in traction, corner exit drive and high-speed stability is immediate. If you want a serious handling upgrade without pressing out the original mount, this is the go-to motorsport solution.

Key advantages

• Motorsport hardness 95A polyurethane for uncompromising control under load
• Insert design fills OEM bush voids to limit cradle shift and flex
• Sharper turn-in and reduced axle tramp and wheel hop on launches
• More consistent alignment integrity for predictable balance lap after lap
• Poly material resists oil, heat and abrasion far better than rubber
• No need to replace the original bush - designed to complement the existing mount

What you receive

• Pair of rear subframe mount inserts - quantity 2
• Diagram reference: 21
• OE cross-reference: 33316792510

Vehicle compatibility

BMW 4 Series F32 Coupe, F33 Convertible, F36 Gran Coupe.

Who is it for

Ideal for track days and competition where chassis control and feedback matter. Also suits fast-road drivers seeking a more connected rear end with minimal compromise.

Installation and support

Professional fitting recommended for best results. For expert installation and setup, choose MJ Modifications in Warwickshire. Request a quote at info@mjmodifications.co.uk.

Why enthusiasts choose this kit

Proven on our builds with consistently positive customer feedback, this rear cradle insert kit delivers a planted feel, improved throttle-on traction and confidence when pushing hard. It is a high-value suspension upgrade that complements coilovers, alignment upgrades and performance tyres.

Search-friendly terms

BMW F32 F33 F36 rear axle carrier inserts, BMW 4 Series rear cradle bush infills, performance poly bush kit, subframe mount reinforcement, uprated rear mounts, polyurethane void filler, track day suspension upgrade, rear subframe mount kit, competition bushing set, 95A poly insert, Powerflex Black compound, PFR5-1921BLK, OE 33316792510.