BMW 3 Coupe E92 Front Left Sideskirt 8045421 51778045421 Original

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We have part number 51-77-8-045-421 in stock and ready to send, with free next-day delivery in the United Kingdom.

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BMW 3 Coupe E92 Front Left Sideskirt 8045421 51778045421 Original - part number 51-77-8-045-421

BMW 3 Coupe E92 Front Left Sideskirt 8045421 51778045421 Original - part number 51-77-8-045-421 - view 2 BMW 3 Coupe E92 Front Left Sideskirt 8045421 51778045421 Original - part number 51-77-8-045-421 - view 3 BMW 3 Coupe E92 Front Left Sideskirt 8045421 51778045421 Original - part number 51-77-8-045-421 - view 4

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About part number 51-77-8-045-421

A sideskirt is an exterior body panel that attaches along the lower sill on the left-hand side of the vehicle, running between the wheel arches. It forms part of the bodywork and helps to smooth airflow along the side of the car while protecting the metal inner sill from road debris, water and stone chips. When it is correctly fitted, it sits flush with the surrounding body panels and gives the lower edge of the vehicle a clean, finished appearance.

To confirm that this part is correct for your vehicle, you must check the part number stamped into the plastic on the reverse side of the panel. The numbers to match for this item are 51-77-8-045-421 or 8045421. Comparing these digits directly against the number on your original component is the only way to guarantee a correct fit, as visual shape alone is not enough.

These panels are usually replaced after suffering impact damage from kerbs, speed bumps or loose road debris, which can cause the plastic to crack or snap. When installing a replacement sideskirt, you will commonly need new plastic mounting clips and bottom fixings, as the original plastic fasteners often break or lose their tension when the old panel is removed.

  • Part type: Other Exterior Parts & Accessories.
  • Specification: manufacturer BMW; country of origin Germany.
  • Position on the vehicle: Front Left.
  • Also numbered: 8045421.

About this kind of part: alloy wheels

An alloy wheel is a cast or forged aluminium wheel. Four numbers describe it and all four have to match the car: the diameter in inches, the rim width in inches followed by the letter J, the number of bolt holes with the circle they sit on in millimetres, and the offset, marked ET, which is how far the mounting face sits from the centre line. A casting number is marked on the back of the spokes or inside the rim, and that number is what identifies the exact wheel rather than one that merely looks the same.

Why people replace one

  • A kerb has taken the paint or the lacquer off the outer rim, which is cosmetic but shows from across the road.
  • A pothole has put a flat spot or a bend in the rim, which makes the steering shake at speed and will not balance out.
  • The lacquer has lifted and the aluminium underneath has gone white and powdery, which spreads once it starts.
  • One wheel of a set has been lost or damaged beyond use, and a matching single is needed rather than a new set of four.
  • A change of tyre size or a seasonal set means a second set of wheels is wanted.

Fitting it

  • The bolts or nuts must be the correct type for the wheel. A tapered seat and a radius seat are not interchangeable, and the wrong one will work loose.
  • Centre caps and the trim rings around the bolt holes are separate parts and are specific to the model.
  • A wheel fitted to a car with tyre pressure monitoring needs a sensor in the valve, and the sensor may need pairing to the car.
  • Wheel bolts must be tightened to the figure in the handbook, and checked again after a short distance.

Making sure it is the right one

  • Match the casting number from the back of the wheel. Two wheels can share a diameter, a width and a bolt pattern and still be different parts with a different offset.
  • The offset matters as much as the size. A wheel with the wrong ET figure will sit too far in or too far out, and can foul the suspension or the arch.
  • Check the bolt circle exactly. Five bolts on a 108 millimetre circle and five on a 110 millimetre circle look identical and will not both fit.
  • If a tyre is fitted, read its size from the sidewall and check it against the rim width. A tyre size that cannot sit on the rim in front of you means the rim marking has been misread.

What to look for in the photographs

A Casting number — Raised or stamped on the back of the spokes or inside the barrel. A wheel often carries several numbers in several places, and this is the one that identifies the part.
B Size and offset markings — Cast into the back of the wheel as a diameter, a width with the letter J, and an ET figure. All three have to match your car.
C Outer rim edge — Where kerb damage shows first. Look along the whole circumference, not just the part facing the camera.
D Bolt holes and seats — The seats the bolts tighten against. Check the shape of the seat as well as the number of holes.
E Centre bore and cap seat — The large central opening and the lip the centre cap clips into. The cap is a separate part.
F Face finish — Painted, machined, diamond-cut or polished. A diamond-cut face cannot be touched in without re-cutting, so the finish is part of what you are matching.

This section describes alloy wheels parts in general. The numbers and the photographs above are this part.

Parts we have that go with this one

Most repairs need more than one part, and these came off the same area of the vehicle. Each has its own page, which says whether we have one in stock today.

Free next-day delivery in the United Kingdom Sent with DPD on a tracked, next-day service. Most mainland addresses are next day; the Highlands and Islands, Northern Ireland, the Channel Islands and the Isle of Man can take a day longer.

Returns Thirty days to change your mind, and we pay the return postage in the United Kingdom and Germany.

Trade and VAT C.E.J Haime Group Limited is VAT registered in England and Wales, and every order comes with a full VAT invoice.

Not sure it is the right part? Send us your registration or VIN and we will check this part number against your own vehicle before you buy.

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