How to Service the Steering Head Bearing on a BMW/5

“Although it may seem daunting, this is a maintenance project within the scope of the average weekend warrior.”

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by Keith Fellenstein

Steering head bearings seem to be one of those things we don’t think about until we have to. The problem is, by the time you realize your bike’s steering head bearings need attention — evidenced by notchy, stiff or even loose steering — it’s usually too late to do anything but replace them. And unfortunately, it’s one of the most common problems you’ll find on older bikes. Because it’s a time-intensive job — i.e., expensive — owners often avoid having it done unless it’s absolutely critical; there’s that too late thing again. And because it involves a fairly comprehensive front end tear down, many owners are scared to do the job themselves.

In the Sixties and Seventies, the average bike used ball bearings in the steering head. Simple, cheap and effective, they’re also prone to wear. Although widely used today, back then tapered roller bearings were usually only found in race frames. Effective in high-speed, high load-bearing applications, tapered roller bearings are superior to ball bearings thanks to greatly increased contact area. That’s a fact BMW appreciated when they specified tapered roller bearings for the steering head and swingarm on all “slash” 5 models. Introduced in 1969, the /5 and subsequent /6 and /7 range evolved to incorporate at least eight different engines in multiple body styles. Translation: There are lots of them out there.

And high build quality means a lot of those old Beemers are still on the road today, with many showing impressive miles. Yet even in the hands of a sympathetic owner, most have likely never had the steering head bearings properly serviced.

That was definitely the case with our subject bike, editor Hall’s 1973 BMW R75/5. Hall’s bike has at least 50,000 miles on it (the speedo gave up the ghost long ago), and our tear down suggested we were the first to disassemble its steering head. Predictably, and underscoring BMW’s wisdom in choosing tapered bearings, we found the bearings were in good shape, needing nothing more than a thorough cleaning and regreasing. The bearing races weren’t pitted, scored or showing signs of excessive scalloping; uneven wear evidenced by radial lines in the bearing cup. Scalloping is a fairly common issue with steering head bearings, due to the steering stem’s limited range of motion, and leads to notchy steering and poor handling.

Although it may seem daunting, this is a maintenance project within the scope of the average weekend warrior. The key is budgeting plenty of time. Don’t expect to complete the process in one day. Instead, be satisfied if you get it done over the course of a weekend. And when you’re done, you’ll have the satisfaction of knowing your steering stem has been properly serviced, ready to give you many more years of confident riding. As always, have a good shop manual at your side to help guide you and to supply critical torque specs.

  • Updated on Oct 5, 2021
  • Originally Published on Sep 29, 2021
Tagged with: BMW R75/5, head bearing, how-to, maintenance
Motorcycle Classics Magazine
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