by Kyle McBride
Chopper motorcycle image by itsallgood from Fotolia.com
Harley-Davidson motorcycles use a chain-driven primary system to transmit power from the engine sprocket to the clutch housing. The clutch pack drive plates mate with the clutch pack plates to drive the transmission mainshaft. The primary chain case cover contains Harley primary chain case lubricant which lubricates the clutch pack and primary chain. Failure of the primary chain case cover gasket or either of the two inspection cover gaskets will cause a leak and will need to be replaced.
Chain box drain
Start the motorcycle and ride until it reaches operating temperature. Park the motorcycle on level ground. Remove the negative battery cable bolt with a 10mm wrench. Remove the negative battery cable from the battery post.
Place a drip pan under the main chain case drain plug. Remove the five retaining screws from the clutch inspection cover with a ratchet and Allen screwdriver and remove the cover from the main housing.
Remove the drain plug from the main chain case. Allow the lubricant to drain completely from the chain case. Remove any debris or metal salt from the drain plug magnet. Inspect the drain plug o-ring for signs of wear or damage and replace if necessary.
Install the drain plug. Tighten the drain plug to 14 to 21 foot-pounds with a 3/8-inch torque wrench and socket.
Remove the cover
Remove the driver and passenger floor board mounting bolts from the frame with a ratchet and Allen screwdriver. Remove the floorboards from the vehicle.
Remove the jiffy bracket bolts with a ratchet and socket. Remove the jiffy bracket. Loosen and remove the gear lever bolt with a ratchet and Allen screwdriver. Slide the shift lever and rubber spacer off the shift lever shaft.
Remove all bolts from the primary chain case cover with a ratchet and Allen screwdriver. Pull the cover away from the inner chain box.
Scrape old gasket material from gasket surfaces with a gasket scraper. Clean the inside of the cover with a shop rag.
Lift the primary cover and new gasket into place. Loosely install all cover bolts. Tighten the cover bolts to 108 to 120 inch-pounds with a 1/4-inch torque wrench and Allen screwdriver using a star pattern.
Install the shift lever and lever bolt. Tighten the lever bolt to 18 to 22 foot-pounds with a 3/8-inch torque wrench. Install the floorboards and floorboard mounting bolts. Tighten the bolts to 30 to 35 foot-pounds with a 3/8-inch torque wrench and Allen screwdriver. Install the jiffy bracket and jiffy bracket mounting bolts. Tighten the bolts to 15-20 foot-pounds with a 3/8-inch torque wrench and Allen screwdriver.
Add 38 fluid ounces of Harley primary chain case lubricant to primary through clutch inspection hole. Install a new clutch inspection cover O-ring on the cover and place the cover over its hole. Tighten the inspection cover bolts to 108 inch-pounds with a 1/4-inch torque wrench and Allen screwdriver using a star pattern.
Install the negative battery cable to the negative battery post. Install the battery bolt and tighten it securely with a 10mm wrench. Start the vehicle and check for leaks around the primary and clutch covers.
- Torque specs given are for a late model FLT. Check the torque specifications for your motorcycle year and model.
Articles will need
- 10mm wrench
- Allen controller set
- Catch pan
- Joint scraper
- Shop rag
- New primary board
- 1/4-inch torque wrench
- 3/8 inch torque wrench
- Harley-Davidson Primary Chain Case Lube, 38 Fluid Ounce