Description
**4137 640 0100 STIHL GEAR HEAD**
**ITEM SPECIFICS:**
– Condition: New
– Brand: STIHL (or specify aftermarket)
– MPN: 4137 640 0100
– Part Type: Gear Head / Gearbox Assembly
– Shaft Size: 25mm / 25.4mm tube compatibility
– Drive Type: 5mm x 5mm square drive
– Thread Size: M10 x 1.00 Left Hand
– Includes: Left-hand nut & splined washer (where applicable)
– Compatibility: See Compatible Models Below
– Type: OEM Replacement / Aftermarket Replacement
**DESCRIPTION:**
Replacement Gear Head Assembly
Part : 4137 640 0100
Brand New
• Complete gear head / gearbox assembly for STIHL brushcutters and trimmers
• Replaces OEM part number 4137-640-0100
• Features 5mm x 5mm square drive shaft
• M10 x 1.00 left-hand thread for blade attachment
• Compatible with 25mm / 25.4mm diameter drive tubes
• Includes mounting hardware where applicable
• Direct bolt-on replacement – restores cutting head function
**COMPATIBLE MODELS INCLUDE :**
**FS Series Trimmers/Brushcutters:**
FS36, FS40, FS44, FS45, FS55, FS65-4, FS72, FS74, FS75, FS76, FS80, FS80R, FS83, FS83T, FS85, FS85R, FS85RX, FS85T, FS87, FS87R, FS90, FS90R, FS94, FS100, FS100R, FS100RX, FS100X, FS110, FS110R, FS110RX, FS110X, FS120, FS120R, FS130, FS130R, FS200, FS200R, FS220, FS240, FS240C, FS240R, FS240RC, FS250, FS250R, FS250RC, FS260C, FS260RC, FS400, FS450, FS460C, FS460RC, FS-KM, FS25-4
**FR Series Backpack Units:**
FR85, FR85T, FR130, FR130T, FR220, FR350, FR410C, FR450, FR460, FR460TC, FR480, FR480C
**Other Models:**
FT100, HL90, HL95, HL100, FS240C, FS240RC
**FITMENT NOTES:**
Verified aftermarket and OEM replacement part for STIHL 4137 series gear heads. Compatible with both early and late model trimmer designs. Some listings include trimmer head with purchase .
Check your equipment model and existing part number before purchase.
**KEYWORDS:**
4137 640 0100, STIHL gear head, gearbox assembly, FS80 gear head, FS85 gearbox, FS90 trimmer head, FS120 gearbox, FS200 gear head, FS250 gearbox, FR450 gear head, brushcutter gearbox, 4137-640-0100, 41376400100, STIHL trimmer gearbox, replacement gear head, mower gearbox
