Exhaust System Resonator Specification Example for City Buses: OEM Replacement
Exhaust System Resonator Specification Example for City Buses: OEM Replacement
This is a worked specification for exhaust system resonator in a oem replacement programme. It is the document we would send a buyer who asks what exactly they are getting: the material, the dimensions that are actually controlled, the finish, and the checks that happen before anything is packed.
The oem replacement version exists because the duty cycle on city buses is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually warranty claims traced back to a single lot.
Example specification
| Item | Exhaust System Resonator |
|---|---|
| Application | City Buses |
| Version | OEM Replacement |
| Base material | Carbon Steel |
| Controlled dimensions | 5 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | zinc plated |
| MOQ | 200 pieces per specification |
| Sampling | 14 working days, 3 days per revision |
| Compliance | DOT |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Carbon Steel, in this example.
- List the dimensions that are actually controlled and the tolerance on each.
- Name the finish and what it has to survive.
- State the inspection level and who pays when a lot fails.
Processes involved
- CNC machining
- anodising
- laser cutting
- rubber vulcanisation
- die casting
- precision stamping
Where this example applies
Programmes that run oem replacement most often specify this build for city buses. Related applications include utility trailers, fleet maintenance, trailer axles, light trucks, agricultural trailers.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 2.5 sampling on the finished lot.
- Finish inspection under agreed lighting.
- Carton drop test on the first lot of a new packing specification.
Questions buyers ask
What happens if a lot fails inspection?
The lot is re-inspected against the golden sample, and replacement pieces ship on the next available booking at our cost.
How long does sampling take?
Samples leave the factory in 14 working days, and each revision round adds about 3 days once you have seen the first piece.
Can you match an existing sample?
Send a sample and we will reverse-engineer the specification, then produce a counter sample for approval before any bulk starts.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the DOT-compliant build instead of a fresh interpretation.
Send the part number, the annual volume and the target market, and we will come back with a specification and a sampling plan.
