Restore max power transfer, crisp clutch engagement, and high-speed cutting performance to your heavy-duty chainsaw with the Genuine OEM STIHL 3/8" 8-Tooth Sprocket Drum Kit (Part #1122 640 2000). Designed as an exact direct-fit replacement, this heavy-duty steel drum assembly swaps out grooved, worn, or heat-damaged drive components—stopping chain chatter, drive link burring, and clutch slippage instantly.
Why Choose Genuine OEM over Aftermarket? Commercial-grade 80cc to 90cc+ forestry saws subject drive components to severe rotational force and high RPMs. Cheap aftermarket drums frequently suffer from out-of-round machining, soft metal drive teeth that groove rapidly, and improper drum wall tolerances that destroy clutch pads. Genuine STIHL drive components guarantee exact dynamic balance, precise needle bearing fitment, and long-lasting commercial durability.
What's Included
- (1) Heavy-Duty Clutch Drum
- (1) 3/8" 8-Tooth Drive Sprocket
- (1) Precision Clutch Washer
- (1) Factory E-Clip Retaining Ring
Key Features
- 100% Genuine OEM STIHL Quality: Built to exact factory specifications using high-density, heat-treated structural steel alloys for maximum service life under severe cutting loads.
- High-Speed 3/8" Pitch 8-Tooth Gearing: The larger 8-tooth profile increases chain speed for rapid bucking, limbing, and fast wood removal on high-displacement engines.
- Induction-Hardened Steel Drive Teeth: Precision-ground teeth resist premature grooving to keep chain drive links meshing smoothly and safely.
- Direct Drop-In Replacement: Engineered to restore crisp clutch engagement and eliminate unwanted drive line vibration.
- Complete Replacement Hardware: Includes required drive line washer and retaining clip to ensure a fast, reliable installation.
Product Specifications & Compatibility
| Brand / Tier | STIHL® Genuine OEM Component Kit |
| Part Number / SKU | 1122 640 2000 (1122-640-2000 / 11226402000) |
| Chain Pitch / Teeth | 3/8" Standard Pitch | 8-Tooth (8T) |
| Kit Contents | Clutch Drum, Drive Sprocket, Clutch Washer, E-Clip |
| Verified Compatible Models | • 064 Series: 064, 064 R, 064 RW • 066 Series: 066 M, 066 MR • MS 650 Series: MS 650 Magnum, MS 650-R Magnum • MS 660 Series: MS 660 Magnum, MS 660-R Magnum • MS 661 Series: MS 661 Magnum, MS 661-R Magnum, MS 661 C-M Magnum, MS 661 C-M R Magnum |
| Note | Needle bearing sold separately. Always inspect bearing during replacement. |