PFR5-1921 – Rear Subframe Rear Insert – M135i M140i M235i M240i

The Powerflex PFR5-1921 Rear Subframe Rear Bush Insert is a Road Series polyurethane insert designed to stiffen the rear subframe mounting point on BMW F2X/F3X models, including the M135i, M140i, M235i and M240i. This insert fills the voids in the OEM subframe bush to reduce flex, improve rear stability and give the chassis a tighter, more controlled feel — without the harshness of a full replacement bush.

SKU: PFR5-1921
Position: Rear Subframe – Rear Bush Insert

Key Features

Road Series Polyurethane

– Stiffer than OEM rubber with daily-road comfort
– Reduces unwanted subframe movement
– Enhances handling precision without excessive NVH

Improved Chassis Stability

– Reduces rear-end float and flex
– Improves vehicle balance under hard cornering
– Keeps the rear subframe properly aligned under load

Sharper Driver Feedback

– More predictable rear axle behaviour
– Better stability during acceleration and direction changes
– Ideal for tuned daily-driven M-Lites and fast-road setups

Easy, Effective Upgrade

– Inserts into the OEM bush (no press tools needed)
– Quick installation
– Noticeable improvement for minimal cost and effort

Benefits

The PFR5-1921 insert tightens up the rear of the F2X/F3X chassis, giving the car a more planted and confident feel. It reduces subframe flex, improves traction and sharpens the overall driving dynamics, making it a perfect upgrade for M135i/M140i/M235i/M240i owners wanting better rear-end control without going full Black Series.

Fitment

Suitable for:
– BMW M135i (F20/F21)
– BMW M140i (F20/F21)
– BMW M235i (F22/F23)
– BMW M240i (F22/F23)
– Also suitable for other RWD F2X/F3X models

SKU: PFR5-1921
Position: Rear Subframe – Rear Insert

Installation Notes

– Installs into the factory rear subframe bush
– No bush removal required
– Slight NVH increase possible
– Professional fitting recommended

About Powerflex

Powerflex Road Series bushes provide enhanced stability and control while maintaining comfort for daily use. Designed to last longer and perform better than OEM rubber, they’re ideal for fast-road and tuned BMW builds.