Plunger springs, head bearings

Restoration forum Bmwbike.com
Post Reply
Ben Friedl

Plunger springs, head bearings

Post by Ben Friedl »

Hi Mark,

I've just ordered the tapperd roller bearings to replace the loose ball bearings in the steering head. The old ball races are stuck tight in the head do you have any idea of how I can remove them without damaging the head.
Also, the plunger springs I've discovered unscrew in a clockwise direction, after being told the opposite. I've managed to free one but the other on the drive side is really tight, there is no drilled hole on the cover to fit a pin wrench as the book suggests. Any tricks on freeing them apart from brute force.

Thanks
Ben
Mark Huggett

Re: Plunger springs, head bearings

Post by Mark Huggett »

Hi Ben,

Your parts left this morning. Re steering head bearings, If you have an argon arc welding machine, the easiest way is to run a small weld on the bearing race. The bearing race contracts and falls out.

Re rear plunger, We have also ruined many a spring cover which was really tight. Best bet is to use penetration oil a few days before the release attempt. Drill a new hole about 8mm in diameter in the spring cover so that you can insert a suitable drive into the hole and locate the start of the spring to tap on. Warmth from an industrial hot air blower also helps though it makes a mess and stinks like hell when the penetration oil gets warm.

Good luck and best regards,

Mark
Mark Huggett GmbH
Pierre Michaud

Re: Plunger springs, head bearings

Post by Pierre Michaud »

Ben,

I just finished replacing my head bearings for the taperred roller set purchased from Mark. I hate to say this but I used a hammer and a screwdriver! The operation went extremely well and the original races did not sustain any damage. The races on the steering head were tapped out systematically from the inside of the neck using a long screwdriver with a slightly bent tip. Care was taken to tap lightly and crossing diametrically frequently. Even on the first tap you could see the race seperating. As for the other races, a thin screwdriver was used to separate the bottom race from the fork yoke and a suitable aluminium tubing was used to knock out the nut. Inserting the roller bearings was another story but nevertheless went well despite my fears. I used various diameter homemade tube drifts one of which was an ABS pipe and another an aluminium ring that I found in my odds and ends. I also used the old races when I was tapping in the new rollers on the top nut in order to protect the rollers (the outside ring is lower than the roller segment and using the race allowed me to tranfer the impact on the outside ring! The main thing is to plan your work and always question your next move and above all keep your cool!
Post Reply