Powerflex Black Series Rear Subframe/Crossmember Bush/Bushing Insert Kit (Pair) for BMW 3 Series F30 F31 F34 F3x (Saloon/Touring/GT) – Polyurethane Cradle/Axle Carrier Mounts – Track/Race – PFR5-1921BLK – Replaces OE 33316792510

Rear Crossmember Insert Bushings for BMW 3 Series F30 F31 F34 - Powerflex Black Series

Part number: PFR5-1921BLK

Replaces OE reference: 33316792510

Diagram reference: 21

Transform the way your F30 platform BMW feels with these motorsport-grade rear axle carrier insert bushings. The Powerflex Black Series compound is engineered for competition use and slots into the voids of the factory rear cradle mounts to cut deflection, steady the chassis and give a more connected, confidence-inspiring drive. Expect crisper steering response, a more planted rear end and better traction when accelerating out of bends on track or spirited road drives.

We use these inserts on our own builds at MJ Modifications and customer feedback is consistently positive. Immediate improvement in rear end composure, tighter line holding and a more predictable car at the limit without the hassle of a full bush replacement.

Why this upgrade works

• High-durometer Black Series material at 95 Shore A to control geometry under load
• Insert design occupies the cavities in the OEM rear sub-frame mounts to reduce movement
• Sharper turn-in and increased stability in fast direction changes and hard braking
• Improved grip and traction on corner exit for track days and fast road use
• Quicker install than pressing out original bushes since the OE rubber remains in place
• Polyurethane resists oil, salt and heat far better than standard rubber for long-term performance

Vehicle compatibility

BMW 3 Series on the F3x platform:
- F30 Saloon
- F31 Touring
- F34 Gran Turismo

If you are unsure on fitment, contact us and we will be happy to help.

What is included

• Pair of rear sub-frame insert bushings - 2 pieces
• Black Series specification for competition-focused setups

Ideal for

• Owners wanting an uprated rear suspension feel without a full bush replacement
• Track day, time attack and performance road builds seeking tighter chassis control
• Drivers chasing a more precise, planted rear axle on the F30 F31 F34 platform

Fitting service

Professional installation recommended. MJ Modifications offers in-house fitting in Warwickshire. For a quote, email info@mjmodifications.co.uk.

Notes

• Black Series is intended for track and motorsport applications
• Expect an increase in NVH compared with factory rubber mounts

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