Hi everyone,

Working on my first custom build ever I’m in the process of stripping back to bare engine to give everything a proper clean (the aluminium has horrendous oxidisation but that’s for another post) but got stuck at the yoke top nut.

A gallon of penetration fluid, heating the nut and letting cool have all yielding zero success.

Has anyone else experienced this situation and have any tips?

Yours ever hopefully,
Al

Try a mix of acetone and ATF 50-50 mix. Create a dam out of plasticine and let it soak, the longer the soak the better. You will have to top up the dam . If you have access to a compressor and a impact gun this will help but soak first.
Regards Martin.

Martin thank you so much for the prompt reply!

Sadly no access to an impact gun so will try the damming technique. Will let you know how that goes!

Al

Follow Martin's advice. When ready to try, use a 1/2" drive breaker bar with a good 30mm 6-point socket and an extension pipe on the breaker bar for leverage. Two people helps. One to hold pressure on the socket so that it doesn't slip; the other to apply torque to the breaker bar. Apply steady pressure to the bar. Make sure the tank and stanchions are removed so that they don't interfere. It should eventually give way.

You mention letting the nut cool.  You need to heat the nut and apply the wrench BEFORE it cools.  Heat it quickly to minimize the heat that will leak into the stem.  The idea is to expand the nut with heat so it doesn't grip the stem so hard.

And as RBM mentioned, use a 6 point socket, anything else will risk rounding off the points on the nut.

Thanks all, will let you all know how it goes!

Hi Everyone, 

Finally found the time to attack the nut and hey presto the soaking, 6 point socket and breaker bar with a friend worked a treat.

Martin, robmack and Point-Seven-five, thank you very much for your help. 

Now onto the job of replacing the bearings...

-Al

Hi, check out Chis Harris’ U-tube page.  There is a whole segment on replacing steering head bearings you might find useful. Cheers Mark

When you get the outer races out (and assuming you haven't resorted to the welding trick), save them somewhere. They make great drifts for seating the new races.