Rebuilding the Clutch

With all the work we've been doing on the top end, along with a history of clutch failure of a riveted spring plate on the Harley Sportster clutch, Steve suggested we should swap out the friction plates with something a bit more durable. When I drained the primary fluid to get ready for this build, I noticed some metal shavings on the magnet, so it was obvious that something was going on. Thanks to Steve's generosity, we have the new Barnett clutch plates for our little land speed racer.


This job starts by backing off the clutch lever to take some pressure off the clutch. Push the boot up over the top of the turnbuckle, put a 9/16 wrench on the nut and a 1/2 wrench on the turnbuckle to loosen it to release the pressure on the lever.


We also needed to remove the shifter and shift linkage so we could remove the primary case. As well as the pinch bolt and the two main fasteners at the bottom of the primary, it made it a little easier to remove the shifter from the linkage to pull the assembly off the primary.


There were two rubber spacers on the splined shaft I hadn't noticed until I had the shifter assembly off. 


Once you have the derby cover off, you'll want to remove what they call the outer ramp and fish the clutch cable barrel end out and set it aside. There is a keyway on the primary case to facilitate removing it.


You'll also need to back off the primary chain tension with the tensioner adjustment on the bottom of the primary. You'll need to insert your allen into the adjustment shaft and loosen the nut that locks the assembly with an open-end wrench. Because I couldn't photograph the two-handed job, I'm using the red arrow to show where you insert the allen.


Now it's time to remove the primary cover and set it aside. I did the same thing with the primary cover fasteners I did with the cam cover fasteners. It might be unnecessary, but it makes keeping track of them easier.


There are other ways to do this, including making your own tool for this job, but Steve will be bringing his bike down to ride with me as I do some break-in miles and we'll be replacing the friction plates on his bike, and my daughter's boyfriend Matt rides a Sportster, so there will be other opportunities to use the tool. In fact, the plan is to tackle this on Steve's bike when he comes down next.

What's more, the Motion Pro Clutch Spring Compressor, while not cheap, wasn't so expensive I didn't want to have it for this job. I've learned over the years that having the right tool for the job makes a big difference.


The most challenging part of this job was removing the retaining ring so you can pull the pressure plate off the clutch basket. I think I had a choice word or two for it as I was trying to remove it (I just couldn't find an easy way to do it) and putting it back on was only marginally easier. Yet, once that ring is removed, the tool and the rest of the spring and plate will come right off.


I used a small pick with a 90 deg bend to coax the friction plates and the steel plates out of the clutch basket. The primary has been dry for a while, so they didn't slip out quite as easily as they did on Jim's Road Glide, but they weren't difficult to remove. You can see in the image above, the riveted spring plate had failed and the idea of changing the friction plates was validated. I don't need to worry about the metal shavings in the clutch any more.


Start with a friction plate and then alternate back and forth between the steel plate, then friction plate until they are all installed. The riveted spring plate Harley uses is not needed with the Barnett set.

Barnett recommends you soak the friction plates in primary oil for 15 or so minutes before you install the plates. I put them in oil when I started the job, which was plenty of time. 

I really like the Red Line Shockproof that's in the Transmission of my Road King, so when I got the Buell I wanted to know what Red Line recommended for the Sportster primary since the transmission and primary share the same gearbox. Shockproof Light is what they recommended—and it happens to be very blue.

In reverse order, you'll now want to reinstall the pressure plate and spring, reinstall the retaining ring, and get ready to close the primary case.


I put some gasket sealer on both sides of the gasket and slipped the primary cover back into place. You'll want to make sure you reach underneath to lift the primary chain over the adjuster when you do. Torque the fasteners to spec and reconnect the clutch cable to the outer ramp.


Somehow I forgot to get a picture of making the clutch adjustment, but insert a slotted screwdriver into the end of the exposed adjustment stud and tighten (turning left) until it gently seats—then back it off 1/4 turn.


You'll then need to adjust your clutch lever to feel with the adjustment turnbuckle. When done, replace the boot over the turnbuckle.


Remove the inspection window and with the adjustment stud on the bottom of the primary adjust so you have 3/8" to 1/2" of deflection on the chain. I used a screwdriver to test. I'm somewhere between the two measurements. Replace the inspection window (and you know me by now, I also replaced the o-ring).


Fill the primary with oil, replace the o-ring on the derby cover, and install the derby cover (don't forget the small spring). Torque to spec. The job is now done.


Tomorrow's project will be to finish putting her back together so this weekend I can start on her breakin miles. I'm excited to get some miles on her. Provided they pass an initial inspection, my tires are currently in good shape, I need to do some safety wiring (so I'll need to learn more about that), I need to get a deadman shut-off installed, and I have an upgrade to my Super E carb coming from Thunder Jet. Other than that, the big project for this inaugural year at Bonneville is done.