Harley Wheel Bearings | Baggers

Harley Wheel Bearings

A Crash Course

There have been many changes in the wheel bearings that Harley has used over the years. They've used ball bearings, roller bearings, and the factory has recently switched over to a dual-row ball bearing design that is double-sealed to keep out dirt and moisture.

Wheel bearing maintenance is of vital importance, since poorly serviced bearings can bring your bike to a crawl, or even worse, they have the potential to completely lock-up a wheel and cause injury.

We dropped in on our friends at Wheel Works in Garden Grove, California, to check out the differences between the early and late bearings used by Harley-Davidson. Gary at Wheel Works also took a few minutes to explain what to look for when servicing tapered roller bearings and the proper way to clean and repack them with fresh grease.

Even though most recommendations point to cleaning and servicing roller bearings every 10,000 miles or so, Gary makes a point of inspecting bearings at each tire change to ensure his customers are on the safe side.

Before we cleaned and repacked a set of tapered roller wheel bearings, Gary took a few minutes to show us some of the more popular Harley wheel bearing types most often seen at Wheel Works. This is a star-hub wheel bearing used from 1936 to 1965. The cage holds the individual rollers that are loaded into the cage by hand before they are dropped into the hub of the wheel.

This is a single-row ball bearing that Harley used from 1966 to 1972. Gary claims that Harley originally sourced this bearing directly from the agricultural equipment market.

Here we have the taper Timken-style roller bearing that was used by the Factory from 1972 until 1999. The tapered roller did a great job of controlling lateral forces, but still had to be disassembled and cleaned about every 10,000 miles or so.

The sealed double-row ball bearing (on the right) is what Harley uses for wheel bearings at the present time. It replaced the tapered roller bearing used on the left side of the frame and needs no service during its life span of approximately 100,000 miles. It is also double-sealed to resist pressure washing and keep out dirt. Extra care should still be used when pressure washing, ensuring it doesn't get too close the hub. Just because the new bearings are double-sealed does not mean that it's impossible to contaminate it with a constant stream of high-pressure water.

Wheel Works carries these roller-to-dual-row bearing conversion kits by FTM. With the FTM kits you can easily convert '72-to-'99 Harleys to the later-style bearing. The kits include all the necessary spacers and shims to get the job done and are permanently lubed.

Gary was rebuilding a wire wheel for one of his best customers and showed us the proper way to remove, clean, and re-pack the tapered roller bearings on this hub from a late '90s Softail. Gary starts by using a special seal-pulling tool. The seal is removed and tossed in the trash. Never try to re-use an old seal. Besides, they're so cheap there's no reason to try to salvage an old one.

Once the seal is free, the bearing, shims, and spacer can easily be removed for inspection. Make sure to hang on to all the shims and put everything back in the order in which it was removed.

We usually clean our roller bearings in a solvent tank, but Gary recommends against this. He feels that no matter how hard you try, you don't always get all of the solvent out, and any residual solvent will instantly begin to break down the new bearing grease after repacking. Gary wipes as much of the old grease away as possible with a rag and carefully inspects the bearing rollers. If they are blued or discolored by heat damage, or pitted, they are automatically replaced. It is imperative that the bearing race in the hub is replaced along with the new roller bearing, since the race is in essence half of the wheel bearing. Running a new roller on an old race is a guaranteed disaster just waiting to happen.

The cleaned and inspected bearing is loaded into this re-lube tool. A grease gun is attached to the Zerk fitting at the bottom of the tool, and the new grease will force out all of the old grease and any contaminants contained in it. After removing the bearing from the repacking tool, Gary wipes off all of the old grease that has been forced out. Then he liberally coats the outside of the bearing with a little extra new grease before dropping it back inside the hub with the spacers and shims. A new seal is carefully driven in with a seal driver, and we're ready to check out the wheel bearing end-play.

A dial indicator is hooked up to measure the amount of lateral play that the bearing has inside of the hub. Gary recommends 0.003 to 0.007-inch. This hub measures 0.006-inch, so it's given the OK and sent over to be re-laced into the customer's rebuilt wheel.


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