There’s a feeling of power that comes with riding a motorcycle with smooth-shifting gears.
Downshifting into a curve, skyrocketing your RPMs, then shifting back into overdrive, and roasting into the straightaway is how a moto-master rides.
All that art falls out the window with a defective clutch, though.
So if shifting feels clunky, you’ve got a faulty clutch, and you’re probably asking yourself how to fix it.
Here’s How to Fix a Faulty Clutch:
If you have a classic cable-oriented clutch lever, be sure you’ve got the appropriate amount of free play as outlined in your owner’s manual. For hydraulic clutch levers, if the bike is lurching when in gear, bleed the system. If your problem is due to a slipping clutch, replace the clutch plates.
What Causes a Faulty Clutch?
Clutch plates can seize together and prevent you from changing gears. Lack of lubrication and oil can cause the clutch plates to overheat, warp, or fuse, resulting in a seized clutch.
A motorcycle clutch contains clutch plates, generally five or six. When you release the clutch lever, it pulls those plates together. When clasped together, the plates don’t rotate.
When you yank in your clutch lever, it disengages your clutch.
The plates undo and free-spin for as long as the clutch is disengaged, releasing the engine from the transmission, allowing them to rotate at different speeds.
This free-spin is what lets you shift gears; when the clutch is released, it locks the transmission and engine rotations together. If you’ve shifted before releasing your clutch lever, you sealed it into a higher or lower gear.
How to Tell If Your Clutch Is Slipping?
The initial sign that your motorcycle clutch is defective is the sound and feel of high revs, as a failing clutch revs much higher than usual.
The high revs mean that the clutch plate takes longer to engage with the flywheel’s speed and torque.
Eventually, you’ll notice your gas mileage dipping; revving at higher RPMs means the engine is also working harder, and a hard-working motor is a gas guzzler to no end.
Here’s another sign you’ve got a defective clutch—the clutch lever is stuck. A clutch lever can get stuck in the engaged or disengaged positions, and while this might be a bad clutch cable, it’s also a symptom of a faulty clutch.
The sticking lever can indicate that the disks are stuck together or stuck apart due to grime build-up in the clutch. Or, it’s the handiwork of some faulty clutch springs. If your springs aren’t functioning properly, the plates can jam, and once they’re stuck, there’s no splitting them apart.
Hard shifts, another bad omen. When you shift on a bad clutch, it feels chunky and dry, accompanied by a metal clunking sound and bike jerk every time you shift.
What’s the culprit?
Your plates are worn out, so they’re not disengaging enough to engage a new gear.
The plates need to be far enough apart for the teeth not to clash; if they don’t split as far as they need to pull that off, the plates grind together. That grinding causes the loud clunking sound, the jerking, and the dry chinky resistance you feel in the lever.
Once again, this could be a bad clutch cable, but it might be those damaged clutch springs we just talked about too.
And you know you have a bad clutch if you can’t put your bike in gear at all.
You start your bike in neutral, idle for a bit, then go to shift into gear, but the motorcycle won’t go into gear, and you notice the foot-shifter bobbing up and down without evidence of resistance; you’ve got a faulty clutch.
Also check out our article about common problems with the Honda Gold Wing.
3 Things You Can Do to Fix a Faulty Clutch
Here are three things to do when your clutch is faulty:
- Check the clutch release lever and cable for the correct amount of free play.
- Consult the factory repair manual and find out the minimum breadth of the clutch plates and the minimum length of the clutch springs.
- If the measurements are less than the minimum outlined in the bike’s repair manual, I’m afraid it’s time to replace the clutch plates.
Make sure to also read our article about how to tell if motorcycle has bad brakes.
How to Replace a Clutch
Replacing a Clutch is time-consuming and involved, though not excessively complicated, if you have an efficient workspace and the appropriate tools.
If you feel your mechanical skills are less than adequate for the task, it’s a job any decent mechanic can happily knock out for you stress-free.
- Prep the replacement fiber plates by cleaning them and soaking them in engine oil for the hour or so it takes you to set up shop. I’ve heard from mechanics more knowledgeable than I am that roughing up the surface of the new fiber clutch plates on concrete, or similar coarse material, helps them interlock without the extra break-in-period slip. Still, fair warning, I’ve never tried it.
- Get your tools together. You’ll need a torque wrench, a set of sockets, a ratchet (with extension), a large flathead screwdriver, Allen keys, a micrometer, and a gasket scraper. You’ll be draining oil from the transmission when you pop off the side clutch cover, so get something to catch it with.
- Get a shop manual close by. A shop manual for your bike is crucial for torque specifications and comes in handy for installing your assembly in order. We suggest a cleaner to scrub the gasket mounting surfaces, and we recommend using a gasket sealer.
- Replace the clutch springs along with the fiber plates. Replace the metal plates if they display apparent wear.
- Identify the clutch cover and loosen all the clutch cover bolts in a crisscross pattern. But remove them clockwise to keep a precise record of which bolt you pulled from where.
- Mark the hole the first bolt came from with a Sharpie. Pro-tip: line the bolts in order on the sticky side of a strip of tape to make sure you keep them in the order in which you removed them.
- Remove the clutch cover. On some motorcycles, this requires popping off some other components, like the oil filter cover. Use a flathead screwdriver to pry the clutch cover off gently. Got the drain pan we talked about? Good. Use it to catch the oil that’s sure to be leaking out of the engine casing of any wet clutch. Be gentle with your gasket, and set it aside with the clutch cover.
- Here it is, the inside of your clutch assembly. You’ll see the friction plates, a pressure plate (the outside plate), the clutch basket, and a throw-out bearing. The clutch springs are held in place by the pressure plate bolts.
- Detach the pressure plate bolts and springs. The springs and pressure plate should slide right out of the clutch basket. Some plates have what we call alignment marks on the pressure plate and clutch basket. If yours do, make sure you put them to reinstall them correctly, and if they don’t, use that sharpie to mark them up yourself.
- The friction plates and throw-out bearing at the core of the clutch basket should be revealed now that you’ve detached the pressure plate.
- If the throw-out bearing slips off, note the location of any alignment marks and put it back exactly as you found it. The bearing forces on the pressure plate and tightens the clutch springs so the clutch can disengage; very important. On most motorcycles, the throw-out bearing will stay right where it is, but pay attention just in case.
- Detach the clutch plates, one by one. Pile them in the exact order they came off in—tip: the fiber and metal plates alternate. Even if you’re only replacing the fiber plates, keep the old plates together and use them as a guide for installing the new plates. NOTE: Incorrectly installed plates can produce excessive clutch slip and shorten the lifespan of your clutch.
- Place the old clutch plate assembly down, preferably on a towel or old shirt.
- Examine the clutch basket’s inner and outer hubs for wear-and-tear while you have the clutch dissembled. If the clutch basket splines have any notches in them, it’s time for a new clutch basket as well. This isn’t a typical situation, but if that’s the case, you don’t want to put new plates on a faulty basket, trust us.
- Inspect the metal plates for signs of wear, scoring, or other signs of excessive friction. You shouldn’t need to replace the metal plates, but it does happen.
- Use your micrometer to ensure that the plates are the appropriate breadth particularized in the service manual.
- Check for warping. If any of the metal plates show the signs of friction or heat we just talked about, replace the entire set.
- Install the first thick friction plate. Alternate steel and friction plates until the clutch is packed with plates in the order they came out.
- Install the pressure plate, ensuring that the throw-out bearing is still in place.
- Install the new springs and tighten the pressure plate bolts, adhering to the torque specifications in your owner’s manual. These bolts are scanty, so don’t over tighten them, or you’ll strip the hub.
- Check the feel of the clutch lever.
- Reinstall the clutch cover. Since you marked your first bolt out and kept them lined up in clockwise order on a strip of tape, you know exactly where all the cover bolts need to be screwed in. Again, torque down the cover evenly without over-tightening the bolts.
- TEST RIDE!
Please also read our article about reasons motorcycles die when put in gear.
2 Tips to Prevent Issues with the Clutch
Clutch issues can be inevitable on an older bike.
The clutch on any vehicle sees a lot of action, friction, and heat, and these things cause wear-and-tear.
The good news is that there are several steps of maintenance you can perform on your steel stallion to prolong her clutch health:
I. Change the Crankcase Fluids Frequently
Some bikes use a specific oil made for the clutch—crankcase oil. Crankcase oil is heavier than most other oil types.
If your bike uses crankcase oil, you’ve probably heard that it doesn’t require changing as frequently as your motor oil. That’s true, but it’s still a good idea to change out the crankcase oil every other year if you ride regularly.
II. Inspect Your Fluids Regularly
There is a small fill cap you’ve probably noticed by now, sticking out from the side of your engine coat. Untwist that cap until you can stick your finger in and check the fluid level.
Inspect how the fluid looks, too. For example, if you see metal shavings in there, that’s a sign of heavy friction-based wear-and-tear.