Bushing

A bushing, also called a suspension bushing or control arm bushing, is installed at suspension control arms, stabilizer bar connection points, subframe to body attachment points and similar locations, positioned between two metal components. It provides an elastic connection that allows relative motion, whether articulation or torsion, while absorbing road impacts and limiting radial and axial displacement of the suspension kinematic pairs. The tubes are normally carbon steel or aluminium alloy, and the elastomer is natural rubber (NR) or polyurethane (PU).

For a distributor or workshop chain, the difficulty is rarely finding a supplier who can make the part. It is building a range that covers real demand, quoting it honestly and keeping the quality consistent order after order. This guide covers the purchasing side of that work.

Building a Range Plan Instead of a Long List

Bushes are usually ordered for a specific link on a specific platform, so a catalogue sorted only by diameter is hard to sell from. A range plan that groups references by link and by platform turns the same number of part numbers into a usable catalogue.

The first step is normally to export the existing sales history and rank references by movement, then map each fast mover back to the link it belongs to. That mapping is what allows a supplier to quote a kit rather than a bare bush.

Cross Referencing OE Numbers

Replacement demand arrives as an OE number, a competitor number, a vehicle application or sometimes only a photograph and a set of measurements. A workable cross reference file records all of them against the internal reference.

Two errors cost more than the rest. Treating a dimensionally similar part as an exact interchange, when the compound or the void layout differs, produces a complaint that is hard to argue. And recording a superseded OE number without noting the change, so that the counter sells the wrong reference for the later vehicle.

Specification Checks on an Incoming Quote

When quotes come back from several suppliers, comparing price alone is misleading, because the specification behind the price is usually different. The checks below bring the comparison back to comparable ground.

1. Confirm the tube material and wall thickness, not only the diameter, since a thinner shell deforms more easily during fitting.
2. Confirm the compound family and the Shore A range as a range with tolerance rather than a single number.
3. Ask for the radial and axial stiffness values measured on a sample, and confirm the test method used.
4. Ask for the bond test value and the standard it follows.
5. Ask whether the void layout is tooled from your drawing or matched to the original part.
6. Confirm the surface finish on the tubes and the salt spray hours claimed.
7. Ask what happens to the specification if the drawing is silent on a feature, because the answer usually explains the price gap.

Samples, First Article and Trial Orders

A sample that arrives without documents proves very little. A first article submission is more useful, because it ties the physical part to the measurements that matter.

A trial order is worthwhile even where the price is slightly higher, because the cost of a fleet level complaint is far larger than the difference on a small first shipment. Any part that fails during the trial should be sectioned or inspected rather than simply replaced, and the finding fed back to the supplier in writing.

MOQ, Tooling and Landed Cost

The landed cost is the number that belongs in a comparison, not the ex works price. A supplier quoting a lower unit price with a new tool charge on every reference, or with packing and labelling excluded, can be the more expensive option over a year of purchases.

Packaging, Labelling and Private Label

Suspension bushes are heavy, and an unprotected shell edge is easy to damage in transit. Packaging requirements are worth writing into the purchase order rather than leaving to the supplier.

• Parts packed so that the shells and the elastomer are not loaded against each other.
• Inner bags, carton labels and carton quantity stated on the order, with the part number and batch code on both the part and the carton.
• Private label printing where the reference is a house brand, including the label artwork approval step.
• Carton strength and pallet pattern agreed in advance so that the shipment arrives stackable.
• A packing list that matches the carton count, since a mismatch is usually discovered at the receiving bench rather than before dispatch.

Incoming Inspection and Third Party Verification

Third party inspection is most valuable immediately after a tool change, a compound change or a move to a different moulding line, because those are the events that alter a part without altering the drawing.

Supplier Evaluation Points

After Sales and Warranty

A clear claim process protects both sides. Agree in advance what evidence a claim requires, typically the part number, the batch code, the vehicle application, the mileage and a photograph of the failed part in position. Agree also whether the remedy is a replacement part, a credit or a joint investigation, and how long a claim stays open.

Where the same position has failed more than once on the same model, the useful response is not a credit but a review of the specification, which is why the failure records from a warranty process should reach the engineering contact rather than stopping at the accounts department.

Frequently Asked Questions

How many references should a distributor stock?

Cover the fast movers in depth and hold the rest on a quoted lead time rather than in stock. A practical approach is to rank references by movement, keep the top group in multiple carton quantities, and treat long tail references as a stocked special. Grouping kits by link position makes a smaller range cover more repairs.

Should I buy on price or on specification?

Compare on the landed cost with the specification fixed. Two quotes for the same bore and shell diameter can differ in compound, hardness, void layout and bond strength, and those differences show up as noise, uneven wear or early failure rather than as a visible defect at goods receiving. Price is only comparable once the specification is comparable.

Is a new tool always needed for a custom bush?

Not always. For a bore, shell and length that already exist in the supplier range, only the compound or the marking may need to change. A new mould is normally required when the length, flange, void layout or tube wall thickness differs from anything already tooled, and clear tooling ownership and amortisation terms should be agreed before the order is placed.

What documents should accompany each shipment?

A packing list, a certificate of conformance and a batch level dimensional and hardness report as a minimum, with a bond test result where the application is safety related or the part has failed before. The batch code on the carton should match the code on the parts, so that a future complaint can be traced back to a mould, a press and a compound lot.

Wholesale Supply for Bonded Bushes

Bonpora Parts supplies suspension bushes and control arm bushes with carbon steel or aluminium tubes and natural rubber or polyurethane elastomer, built to the bore, shell, length, flange and void layout shown on your drawing, with hardness, stiffness and bond test results available for the production batch. Where an original reference is obsolete or a number is unreadable, send the measurements and a photograph and our engineers will match the closest existing tool or quote a new one. Begin with the mounting bush range, see how failed parts are assessed on the bushing failure analysis page, review the bushing manufacturing and quality control points worth auditing, or contact our team with your specification, target price and annual volume. New dimensions are quoted from drawings or samples under custom moulded and bonded parts, further references are listed on the products page, and the wider chassis and suspension package covers bushes, bump stops and mounting hardware together.