S&S rocker arm shafts for the M8 — a direct replacement for the OEM shaft (H-D part 17300059B), precision centerless ground from bearing-quality steel and 66% stronger than stock, so radical cam profiles don't bend them.
FITMENT
Fits 2017-up Harley-Davidson M8 models. In our catalog: 2017-up M8 Touring models. Direct replacement for OEM H-D part #17300059B (S&S).
Not sure it fits your bike? Email info@norcalbaggersupply.com — email is the fastest way to reach us — and we'll confirm before you order. You can also call 916-626-9030 (Mon–Fri, 9 AM–5 PM PT).
SPECIFICATIONS
Manufacturer: S&S Cycle — part number 900-1090
Direct replacement for OEM (H-D part #17300059B) — S&S
Made from bearing-quality steel, precision centerless ground for perfect fit (S&S)
66% stronger than stock — prevents damage from radical cam profiles (S&S)
S&S recommends installing its Rocker Stud Kit 900-1013 with these shafts
Made in the USA
INSTALLATION
Shafts are replaced with the rocker boxes off, during rocker arm service. Follow the S&S instruction sheet included in the box and your Harley-Davidson service manual for torque specs. No official S&S install video is published for this part — installation is manual-only. Professional installation is recommended.
QUESTIONS RIDERS ASK
Why upgrade the shafts? Stock shafts can flex and wear under high-lift cams. The S&S shafts are 66% stronger (their figure) and ground from bearing-quality steel, so the rocker arms stay where they belong at high RPM.
Do I need the stud kit too? S&S recommends pairing these with their Rocker Arm Stud Kit (900-1013) — the studs extend head life by preventing damage to the rocker arm towers.
