Description

Koehring 6633L-5 Parts Catalog – Factory OEM Parts Reference

You’ve got a Koehring 6633L-5 Logger that needs parts. You don’t need guesswork – you need the factory parts catalog with the exact OEM numbers. I’ve been turning wrenches for 28 years, and I can tell you that ordering the wrong part because you used a generic cross-reference costs more than this manual. 30 pages of nothing but the parts breakdown you need.

This is the factory document.

Operation of this catalog is straightforward. The Parts Group Index organizes everything by functional group. Each group has a letter or number designation. You’ll find that in the table of contents. For example, Crawler & Carbody is Group G.

Crawler & Carbody – Group G

Group G covers the crawler track frames and carbody. These are heavy components that take a beating. The catalog lists every roller, sprocket, idler, and track shoe. If you’re rebuilding the undercarriage, you’ll use this section. Don’t guess at the pin and bushing sizes – it’s all in here.

Why the Serial Number Matters

Koehring machines went through product improvements. The 6633L-5 had different suppliers over its production run. The catalog says: ‘KNOW THE SERIAL NUMBER OF YOUR MACHINE before searching for replacement parts.’ Page 4 spells this out. If you ignore this, you’ll order a hydraulic pump that doesn’t fit. I’ve seen it happen.

Upper Engine & Fuel Tank Parts

This section covers the engine mounting, fuel tank, and associated lines. The Engine group includes gaskets, filters, and manifold parts. Fuel system components – tanks, caps, strainers – are here too. The catalog groups them logically. You don’t have to flip through a wiring diagram to find a fuel line clamp.

Hydraulic System – How to Identify Components

Hydraulic system parts are broken down into pumps, valves, cylinders, and hoses. Group numbers correspond to each subsection. The manual uses a group number 10 for pump drive – that’s separate from the main hydraulic group. This is important: the catalog tells you which serial numbers use which pump. If you’re swapping a main control valve, check the group number first. It’s on page 3.

Logger Attachment: What the Catalog Covers

The 6633L-5 is a Logger, and the attachment section is critical. It covers the grapple, boom, and stick components. These are specialized parts – not off-the-shelf. The catalog lists the entire assembly with part numbers. If you need a replacement cylinder rod, you’ll find it here. No guesswork.

Using the Numerical Parts List

At the front of the catalog, there’s a numerical parts list. It cross-references part numbers to the pages where they appear. The catalog also mentions that block numbers correspond to group block numbers on parts pages. This is how you verify if a part is current. Don’t skip this step.

Electrical System – Group Reference

Electrical system wiring is covered in its own group. The catalog includes switches, lights, alternator, and the Heating & Air Conditioning group. If you’re tracing a short or replacing a starter, you’ll find the exact part numbers here.

This is the original factory documentation. Not an aftermarket copy. For more background on how factory specifications influence machine reliability, see the Automotive Industry Overview. The Automotive Industry Overview covers the evolution of standards.

Does this catalog include part numbers for the Koehring 6633L-5?

Yes. Every serviceable part is listed by factory number.

How do I find the right part for my machine?

You need the serial number of your machine. The catalog has a parts group index on page 3 that directs you to the correct group for your serial number range. For example, Crawler & Carbody is Group G. Then use the numerical parts list to locate the page number. This information is explained on page 4. If you skip this step, you risk ordering an obsolete or incorrect part. Take the time to locate your serial number – it’s stamped on the machine’s frame. That’s the only way to guarantee the part you order matches your build. I’ve had customers order the wrong final drive motor because they used a serial number from a different machine. Check the plate – it’s right by the operator’s cab. That single piece of information saves you from buying a $2,000 part that doesn’t fit.

Are there exploded view diagrams?

The catalog uses group-numbered parts pages with illustrations. Each illustration has callouts tied to the parts list.

Can I use this catalog for other Koehring models?

This catalog is specific to the 6633L-5 Logger beginning serial number 110721. Do not use it for other models. Koehring produced separate catalogs for each model and year. If you need for a different machine, check our related manuals below, such as the Koehring T-S44, 644 1974 Parts Catalog – Factory OEM Parts Reference, Koehring S-155 1977 Parts Catalog – Factory OEM Parts Reference, or Koehring 366 Hydraulic Hoe Parts Catalog – OEM Factory Specs.

Stop spending time on parts counter guessing games. Get the exact number. Access the Factory Manual now.