Rebuilding the Oil Dipstick for a John Deere 675B with Yanmar Power

[MikePhua]

The JD 675B and Its Compact Legacy
The John Deere 675B skid steer loader was introduced in the early 1990s as part of Deere’s compact equipment lineup, designed for tight job sites and versatile material handling. With a rated operating capacity of around 1,500 pounds and a nimble frame, the 675B was powered by a Yanmar diesel engine—an efficient and reliable choice for light construction and agricultural use.
Yanmar, a Japanese manufacturer with deep roots in industrial diesel engines, supplied powerplants for many compact machines across brands. The engine in the 675B was known for its fuel economy, cold-start reliability, and straightforward mechanical design. However, as machines age, sourcing parts like dipsticks becomes increasingly difficult—especially when OEM support is discontinued.
Terminology Annotation
- Dipstick: A calibrated metal rod inserted into the engine’s oil sump to measure oil level.
- Sump: The reservoir at the bottom of the engine where oil collects.
- OEM (Original Equipment Manufacturer): The company that originally produced the part or component.
- Discontinued part: A component no longer manufactured or stocked by the original supplier.
The Challenge of a Broken Dipstick
In one case, the dipstick for a 1994 JD 675B snapped, and the owner discovered that the part was no longer available through John Deere dealers. Without a replacement, checking oil levels becomes guesswork—risking overfill, underfill, or engine damage. The dipstick’s dimensions, markings, and insertion depth are critical for accurate readings.
This situation is common in legacy equipment. As manufacturers phase out older models, low-demand parts like dipsticks, knobs, and brackets are often dropped from inventory. Owners must then turn to salvage yards, cross-brand compatibility, or custom fabrication.
Cross-Referencing Yanmar Engines for Compatibility
Because the 675B uses a Yanmar engine, it’s possible that other machines—such as compact tractors, generators, or marine engines—share the same dipstick design. To identify compatible models:

• Locate the engine model number stamped on the block
  
• Search Yanmar parts catalogs for dipstick part numbers
  
• Compare insertion depth, tube diameter, and oil level markings
  
• Contact small engine repair shops or marine diesel specialists
  

Yanmar’s widespread use in Kubota, Komatsu, and even aftermarket generator sets means that dipsticks may be interchangeable across platforms. However, even small differences in tube length or oil pan depth can lead to inaccurate readings.
Fabricating a Replacement Dipstick
If no direct replacement is available, fabricating a dipstick is a viable solution. This requires:

• Measuring the depth from the top of the dipstick tube to the bottom of the sump
  
• Determining the correct oil level range based on engine specs
  
• Using a flexible but durable metal strip (e.g., stainless steel or spring steel)
  
• Marking the “Full” and “Add” lines based on known oil volume
  

To calibrate the markings:

• Drain and refill the engine with the exact oil capacity listed in the manual
  
• Insert the fabricated dipstick and mark the oil level as “Full”
  
• Remove one quart and mark the new level as “Add”
  
• Test the dipstick after engine operation to confirm accuracy
  

Some operators use old hacksaw blades or flat stock steel, ground smooth and marked with a punch or engraving tool. The key is consistency and repeatability.
Preventive Measures and Long-Term Solutions
To avoid future issues:

• Keep a spare dipstick or record its dimensions in the service log
  
• Use a rubber grommet or cap to seal the dipstick tube and prevent contamination
  
• Check oil levels before each use, especially in older machines
  
• Monitor oil color and viscosity for signs of wear or contamination
  

For machines stored outdoors, moisture can enter through an open dipstick tube, leading to emulsified oil and internal corrosion. A simple plug or boot can prevent this.
Conclusion
A broken dipstick on a John Deere 675B may seem minor, but it underscores the broader challenge of maintaining legacy equipment. With OEM support fading, operators must rely on ingenuity, cross-referencing, and fabrication to keep their machines running. Whether sourcing from a Yanmar-powered tractor or crafting a custom gauge, the solution lies in understanding the engine’s needs and respecting its mechanical limits. In the world of compact loaders, even the smallest part plays a vital role—and a well-marked dipstick is the silent guardian of engine health.