The Wacker Neuson is a genuine OEM Piston 0.25 designed for GP3800A portable generators and PT3A centrifugal trash pumps. As a direct Wacker Neuson OEM component, part is manufactured to the same specification as the original piston installed at the factory, ensuring correct bore clearance and ring groove geometry for the shared engine platform used across both machine families. This oversize piston is intended for engines that have been bored out during a rebuild, making it a critical component when restoring worn or damaged cylinders to service. Compatible models include multiple GP3800A generator configurations — including standard, premium, and wheel kit variants — as well as PT3A trash pump variants across several build codes.
Key Features
- OEM Oversize Specification: — Cast and machined to exact 0.25 oversize dimensions, ensuring correct piston-to-wall clearance when installed in a freshly bored cylinder — no guesswork on sizing.
- Shared Engine Platform Coverage: — A single part number covers both the GP3800A generator family and PT3A trash pump family, reflecting the common engine architecture across these Wacker Neuson machines.
- Genuine Wacker Neuson OEM Quality: — Sourced directly from Wacker Neuson, this piston meets the original material grade and dimensional tolerances required for proper compression and ring seal in these engines.
- Rebuild-Ready Component: — Paired with a cylinder bore job, this oversize piston restores compression loss caused by cylinder wear, returning the engine to full power output for demanding pump and generator applications.
- Broad Variant Compatibility: — Fits standard, premium, EPA-compliant, CSA-rated, and wheel kit-equipped GP3800A builds, plus multiple PT3A pump build codes — confirm your machine number before ordering.
A piston is the reciprocating component inside the engine cylinder that converts combustion pressure into the crankshaft rotation that drives your generator or pump. Over time, cylinder walls wear and lose the tight clearance needed to maintain compression, causing power loss, increased oil consumption, and hard starting. An oversize piston like the 5000162634 is used after a cylinder bore — the worn cylinder is machined to a precise oversize diameter, and the matched oversize piston restores the correct clearance, sealing pressure, and power output the engine was originally built to deliver.
Part Details
| Part Number | 5000162634 |
|---|---|
| Old Part Number | 0162634 |
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | 0.25 Oversize Piston |
Compatibility & Fitment
| Name | Model | Machine Number |
|---|---|---|
| Portable Generator | GP3800A | 5000620104, 5000620379, 5000620485, 5000620342, 5000620484, 5000620041, 5000620103, 5000620010 |
| PT3A | PT3A | 5000009101, 5000009240, 5000009098, 5000620800 |
| GP3800A Generator, EPA | GP3800 | 5000620974, 5000620975, 5000620976 |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
