Leaks Suck: Fixing A Leaky Shift Shaft Seal

Article & Photos By: Corey Barnum- Faith Forgotten Choppers

Originally Published In The February 2019 Issue Of Cycle Source Magazine


This month’s tech is focused on some basic service work. Today, we have a customer’s 2011 Road Glide in our shop. The customer was complaining of oil drops on the ground towards the left side of his motorcycle. Upon investigation we noticed that his shift shaft seal was leaking causing the transmission fluid to leak out and end up on the ground. This is a very common leak that does not pose an immediate danger to the transmission. However, leaks suck and we like to keep everything clean and tight here.

In order to maintain safety, I always unhook the battery anytime the primary drive is opened. I also cover the ECM with rubber, so it doesn’t run the risk of arcing between the battery terminals.

After the battery is disconnected, I start by removing the shift levers as well as rider and passenger floorboards. I’ve found removing the shift levers as an assembly makes it easier when it comes time to reassemble the primary.

Draining the primary fluid is the next step in this process. The drain plug for this is towards the back, on the bottom of the inner primary. Once the oil is done draining, I remove the 13 screws holding the cover. The cover is now ready for removal.

With the cover removed, you’ve now gained access to the drive components. The first part that is removed is the throw-out bearing adjuster. I follow that by removing the chain tensioner assembly. Finally, I remove the clutch hub nut and the compensator bolt.

The compensator assembly, chain, and clutch are now easily removed from the bike as an assembly.

With the parts now removed from the motorcycle, it’s time to inspect them for damage. Here you can see the back side of the clutch hub. The splines on the clutch hub are what you should inspect. Make sure none of them are damaged.

The compensator is the next thing I inspect. When doing this there are a few areas of concern. The first is the ramp part of the comp. As you can see this one has significant damage to it and needs to be replaced.

If you have no significant damage to the ramp, the spring pack stack height would be the next to examine. This picture shows how to stack the springs to measure them correctly.

As you can see in the picture, this stack height is under Harley spec for this style of compensator. The spec for the stack height is .286”-.326”

The last thing you should inspect on the compensator would be the rotor that the springs rest on. This is a visual inspection. Make sure the spring hasn’t grooved the rotor in anyway.

After all the drive component have been inspected. You need to remove the 2 starter bolts. A ball allen socket makes getting to these bolts a lot easier.

Remove the 5 inner primary bolts, then the inner primary will just slide right off.

With the inner primary removed, you’ve now gained access to the shifter itself. Remove the allen bolt and take the shifter arm off.

There is a retaining ring holding on the washer. Remove the ring and washer to gain access to the shift shaft seal. I usually use a small pick to get the old seal out of the case.

Install the new shift shaft seal, then began to assemble the primary in the opposite order that you took apart in, making sure to follow all of the proper torque specs.

During the reassembly process the customer approved us to go ahead and replace the compensator. The new compensator comes with an oil slinger that needs to be epoxied to the cover.

With the primary back together. The last step is putting in the fluid.

When primary is all finished, make sure your shop bird approves your repairs.

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