Description
Overview:
The Oil Seal B20x39x4 is a genuine Stihl component designed to seal rotating shafts and prevent leaks in high-performance chainsaws such as the MS 880 and 088. Made from durable, oil-resistant elastomer with a stable form factor, it helps keep lubricants where they should be and protects against dirt ingress. Correct sealing supports consistent engine performance and reduces the risk of premature wear in adjacent parts. With dimensions of 20 mm inner diameter, 39 mm outer diameter, and 4 mm thickness, and Stihl MPN 9640 003 2250, this seal is built to original specifications for a precise fit in the intended housing. It is suitable for routine maintenance or rebuilds where restoring factory sealing is essential.
Key Features:
- Genuine Stihl part for assured compatibility and build quality
- Dimensions: 20 mm ID x 39 mm OD x 4 mm thickness for an exact OEM fit
- Tough, oil-resistant rubber construction for reliable sealing under load and heat
- Helps prevent oil and fuel mixture leaks and maintains proper crankcase sealing
- Supports smoother running and reliable starting by minimising air leaks
- Compact 4 mm profile suits tight engine and clutch-side housings
- Stable fitment reduces the chance of vibration-related seal movement
- Suitable for demanding, professional use in large-displacement saws
- Straightforward to install with appropriate tools and clean seating surfaces
Typical Applications:
Used during engine overhauls, crankshaft or bearing replacements, and when diagnosing air leaks or oil seepage. Ideal as a preventative maintenance part on high-hour machines to restore factory sealing around rotating shafts, maintaining performance in forestry, milling, and heavy cutting work.
Also known as:
Shaft seal, crankshaft oil seal, rotary seal, lip seal, sealing ring, oil ring, engine oil seal, rotary shaft seal.
Fits Models:
084, 088, MS 780, MS 880, MS 881
Alternate Part Numbers:
9640-003-2250, 96400032250
