Bilstein B1 Rear Shock Damper Protection Kit – Dust Cover & Boot, Gaiter & Bump Stop Set for BMW 1/2/3/4 Series (F20 F21 F22 F23 F30 F31 F34 F33 F36 F83) Rear Axle – Shock Absorber Bellows/Jounce Bumper Service Pack – Part 11-305880

Rear Damper Protection Kit for BMW F Series - Bilstein B1 - Part Number 11-305880

Keep your rear suspension working at its best with this genuine Bilstein B1 rear damper protection set, part number 11-305880. This rear axle service kit shields the piston rod from grit, spray and salt while the integrated bump stop cushions full-travel hits to protect your shock absorber and preserve ride quality. Ideal for refreshes, maintenance and performance handling upgrades on BMW 1 Series, 2 Series, 3 Series and 4 Series F-platform models.

Looking for a rear shock absorber gaiter kit, jounce bumper and boot set, rear damper bellows, piston rod sleeve, rear suspension repair kit, or shock protection shroud for BMW F20 F21 F22 F23 F30 F31 F34 F33 F36 F83? This is the exact Bilstein kit you need. We have fitted this part many times at MJ Modifications and customers consistently report quieter suspension, tighter feel and longer damper life after replacing perished OE components.

Why this Bilstein B1 kit is a smart upgrade

• Authentic Bilstein service components for the rear axle
• Precisely matched to Bilstein dampers and OE fitment dimensions
• High quality materials resist cracking, splitting and UV ageing
• Helps prevent seal damage by keeping contamination off the piston rod
• Reduces knocks and clunks caused by collapsed bump stops and torn boots
• Perfect for suspension refreshes, daily drivers and fast-road builds

Product identifiers

• Brand: Bilstein
• Range: B1 accessories and service parts
• Fitting position: Rear axle
• Part number: 11-305880
• EAN: 4025258851941
• UPC: 651860859712

Compatible BMW models and chassis

Designed for BMW F Series rear suspension applications. Common fitments include:

• BMW 1 Series: F20, F21
• BMW 2 Series: F22, F23
• BMW 3 Series: F30, F31, F34
• BMW 4 Series: F33, F36, F83

Popular engine and trim searches matched to this kit: 114i 116i 118i 120i 125i M135i M140i xDrive, 218i 220i 228i 230i M235i M240i xDrive, 316i 318i 320i 328i 330i 335i 340i, 316d 318d 320d 325d 330d 335d, 420i 428i 430i 435i 440i, 420d 425d 430d. If you are unsure, we will confirm by registration or VIN before dispatch.

What you get

• Rear damper boot bellows to guard the piston rod
• Rear travel buffer bump stop to control compression at full stroke
• Direct-fit service kit for an OE-grade refresh

Real-world results

Fitted by us on road and performance builds, this kit delivers a cleaner, better-protected damper, improved longevity and a more refined rear end. It is the go-to choice when installing new shock absorbers or giving tired F Series suspension a proper overhaul.

Professional fitting and support

Installation by a trained technician is recommended. MJ Modifications in Warwickshire offers fitting and alignment services for this Bilstein B1 rear damper protection kit. Request a quote at info@mjmodifications.co.uk.

Compatibility check before dispatch

We will verify suitability prior to shipping. Add your UK registration or the last 7 of your VIN at checkout so we can confirm part 11-305880 is correct for your specific BMW.

Search terms customers use for this item

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