By Justin James
Riding a bike with an improperly functioning clutch can be a pain. You may have trouble shifting or experience some clutch slip or drag. This can often be caused by improper adjustment. Luckily the process to properly set it is not a very tough task. In this edition of Tinker Talk I will demonstrate how to properly adjust a clutch using a Harley-Davidson 5-speed Sportster (‘91 and newer) as my test subject. Follow these steps in this order and you can be assured that the clutch is in proper adjustment.
• Level the bike to prevent loss of primary fluid when derby cover is removed.
• Separate the clutch cable from the frame and access the cable adjuster by sliding the rubber boot down the cable. A quick blast of penetrating oil will ease this process (Photos 1A and 1B).
• Hold the cable clutch adjuster (typically with a ½” wrench) and break the lock nut free (typically with a 9/16” wrench). Both the lock nut and adjuster are standard, right hand threads (Photo 1C).
• Turn the adjuster inward until the cable is fully retracted (Photo 1D).
• Remove the derby cover. In most cases the screws will be a T27 Torx head, but this can vary. Be sure you are using the correct tool to avoid stripping (Photo 2A).
• Remove the lock plate/spring. This will pull straight out if it did not already fall out when the derby cover was removed.
• Using a flat screwdriver, turn the clutch adjustment screw outward (counter-clockwise) until it gently seats (Photo 2B).
• Turn the clutch adjustment screw inward (clockwise) 1/4 turn (Photo 2C).
• Reinstall the lock plate/spring. To do this you will want to line up the flat portions of the plate with the flat portions of the screw. You may have to turn the screw slightly to allow the lock plate to fall into the hex socket in the release mechanism. If you must do this, it is best to rotate it clockwise (Photo 2D).
• Turn the clutch cable adjuster to take the slack out of the cable until there is about 1/8” free play between the cable and the lever perch. Secure the lock nut (Photos 3A and 3B).
• Slide the rubber boot back over the adjuster and reattach the clutch cable to frame.
• Clean any dirt, oil or residue from the gasket mating surface and install a new derby cover gasket. A light film of grease will help keep the gasket in place when installing the derby cover.
• Reinstall the derby cover and torque the bolts to 40-60 in/lbs. using the appropriate pattern (Photo 3C).
You may consider changing the primary fluid and/or lubricating the clutch cable since you are already most of the way there. If properly setting the clutch does not remedy the issues you are experiencing, then a tear-down and inspection should be in order. This inspection would be exceptionally urgent with Sportsters thanks to the dreaded spring plate (aka grenade plate) found in the middle of the clutch pack. This grenade plate has been known to live up to its name even when the clutch is well maintained. Neglect a Sportster clutch and you are flirting with disaster. I’ve seen these things let go and cause significant damage in as few as 15,000 miles. Should you ever need to replace a Sportster’s clutch plates I would highly recommend eliminating the grenade plate by installing a complete extra plate clutch pack. Please note that this specific process only applies to 5-speed Sportster powertrains. In the next edition of Tinker Talk we will cover the clutch adjustment process for 5- and 6-speed Harley-Davidson big twins.
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