NK5 is the RPO code for the standard urethane steering wheel — the hard moulded one, not the leather. It is the code that means your truck got the base wheel.
That sounds like nothing worth a page, and for most owners it is. It matters in exactly one situation: you are ordering a steering wheel, a clockspring or an airbag, and you need to know which part the truck actually takes.
Where NK5 is documented
| Year | How GM described it | Source |
|---|---|---|
| 1983 | “Steering wheel, standard” | GM option master |
| 2022 | “Steering wheel, urethane” | Secondary order-guide transcription only |
| 2025–2026 | “Steering wheel, urethane” | GM Fleet order guides; GM Canada eOGLD |
Sixteen GM-sourced records. The coverage is thin in the middle — no GM-sourced record between 1984 and 2021, only an unverified 2019 entry — because trim-level codes like this one rarely appear in the fleet, police and heritage documents our library is built from. NK5 was in continuous use throughout; we just will not claim years we cannot show you.
What NK5 rules out
This is the useful half of the code. If your label has NK5, it does not have:
- NP5 — the leather-wrapped wheel. The two are alternatives, not companions.
What NK5 does not rule out is UK3, the steering-wheel-mounted controls. A base urethane wheel can still carry buttons, and on fleet trucks it very often does. Those are separate line items and they appear together on plenty of labels.
Why it matters for parts
Steering wheels are not a one-part-fits-the-year affair. The wheel, the airbag module, the clockspring and the wiring behind it are matched to what the truck was built with. Ordering by year alone is how people end up with a wheel whose harness connector does not exist on their column.
Before you buy, confirm three codes together: the wheel (NK5 or NP5), the controls (UK3), and cruise (K34). Between them they describe what is physically on your column.
Upgrading from NK5
Swapping to a leather wheel is one of the cheapest interior improvements on a plain truck, and on older platforms it is genuinely a bolt-on if you match the column. Two things catch people:
- If you are also adding buttons, the clockspring has to carry the extra circuits. A wheel with buttons on a clockspring without them gives you buttons that do nothing.
- The airbag module is part of a safety system. Disconnect the battery and wait before you touch it, and if you are not confident with that, this is a job worth paying for.
How to check yours
- Feel it. Urethane is hard and slightly textured; leather is stitched, and you can find the seam.
- Decode NK5 for your model year, and run the whole label so you pick up UK3 and K34 at the same time.
Sources
- 2025–2026 GM Fleet order guides; GM Canada eOGLD order guide
- GM VPPS option master, November 2002
Related
- RPO Decoder · RPO Code Database
- NP5 — leather-wrapped wheel · UK3 — steering wheel controls · K34 — cruise control
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