Bilstein B4 21-030505 Front Shock Absorber Strut Insert 51mm -

Bilstein B4 Front Strut Cartridge - BMW 3 Series E30 51 mm - Part No. 21-030505

Refresh the front end of your classic BMW with the Bilstein B4 front strut cartridge, part number 21-030505. Engineered to OEM standards with Bilstein’s renowned gas-charged twin-tube design, this 51 mm insert restores factory-spec ride comfort, sharper steering feel and confident road holding on your E30. It is a direct replacement insert for 51 mm MacPherson strut housings, giving you smooth, predictable damping on UK roads without harshness.

We use these on our own builds and customer cars. Feedback is consistently positive, with improved stability under braking, reduced float over undulations and a taut, controlled front axle that still rides beautifully around town.

Highlights

• OEM-spec replacement for 51 mm front strut housings on BMW E30 3 Series
• Gas-charged twin-tube construction for consistent damping and composure
• Comfortable on daily drives, confidence-inspiring on B-roads
• Excellent road feel and grip with predictable body control
• Top pin and bottom plate mounting for a straightforward install
• Built to Bilstein quality standards for durability and long service life

Technical details

Vehicle applications

Fits BMW 3 Series E30 models with 51 mm front strut housings:

• Saloon and Coupe 09.1982 to 03.1992
  • 316, 316i, 318i, 318is, 320i, 320is, 323i, 325i, 325e 2.7, 324td
• Touring 07.1987 to 10.1994
  • 316i, 318i, 320i, 325i, 324td
• Convertible 09.1982 to 11.1993
  • 316i Baur TC, 318i, 320i, 325i
• BMW Z1 Roadster 06.1988 to 06.1991
  • 2.5

Check your front strut tube measures 51 mm before ordering. If you need help confirming compatibility, contact us with your registration or last 7 digits of your VIN.

Why choose this Bilstein B4 insert

• Restores the poised, factory-fresh E30 driving feel
• Enhanced stability and control when cornering and braking
• Perfect for road use and fast A-road touring without compromising comfort
• Trusted by enthusiasts for reliability and long-term value

Professional fitting

Want it installed by specialists who know E30 suspension inside out? MJ Modifications offers professional fitting in Warwickshire. Request a quote at info@mjmodifications.co.uk.

Common search terms

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