When your John Deere’s engine starts knocking or the oil pressure drops, it’s time to take a closer look at those main bearings. After years of hard work—whether you’re pulling a plow, running a baler, or hauling grain—the crankshaft wears down those bearing surfaces. That’s where these 20 thousandths oversize main bearings come in handy. They’re sized for crankshafts that have been turned down to clean up wear and scoring, getting your engine back to proper clearances and oil pressure.
What You’re Getting
- Precision-manufactured oversize bearings that match the exact specifications for turned crankshafts
- Quality materials that handle the stress and heat of diesel engine operation
- Proper oil clearances to restore pressure and reduce engine noise
- Direct fit for multiple John Deere engine families including 4239T, 4039T, 6359T, and others
- Complete set for full engine rebuild or individual replacement as needed
Built for Real Farm Work
These bearings fit a wide range of John Deere tractors from the smaller utility models up through the bigger row-crop and specialty machines. Whether you’re running a 2250 around the farmyard, working ground with a 3050, or pulling heavy implements with a 4050, these engines see plenty of hours under load. The 4239T and 6359T engines were workhorses in their day, and with proper bearing replacement, they’ll keep running for years to come.
Made to Last
Farm engines don’t get babied, and these bearings are built to handle the reality of agricultural work. They’re manufactured to handle the constant load cycles, temperature changes, and contamination that diesel engines face. The bearing material provides proper wear characteristics while maintaining the oil film that keeps your crankshaft protected.
Installation Notes
These are oversize bearings, which means your crankshaft needs to be machined by a qualified shop before installation. The crank journals get turned down 20 thousandths, then these bearings restore proper clearances. Always check your plastigauge clearances and torque specs—getting the main caps right is critical for engine longevity. Most rebuilds also call for new main cap bolts while you’re in there.
