Top yoke nut

[youngjohn]

Is there anything I should know about removing the centre nut on the top yoke (10mm hex)? I've just snapped the end off a quality extension bar trying to remove it and now have the snapped bit stuck in my hex bit.

[balibeemer]

Try using tools that are not made in China!

[youngjohn]

It was a Hazet extension, made in Germany. That's why I'm so surprised.

[montmil]

Now that sounds like a snug nut!

To begin the steering stem bearing replacements in my '83 R65, my first challenge was removing that tough stem nut. I had a 24-inch pipe extension over the handle of a 3/8-inch ratchet with a 10mm Allen bit. A second person held the bike steady. A strong pull finally broke loose the top nut.

Keep at it. After years of time getting a good grip, that nut can be a PITA.  [smiley=wall.gif]

Like Grandpa used to say, When all else fails, get a bigger hammer. He really meant to say, use an air impact gun.

[Barry]

That top nut is seriously tight and near everyone struggles with it. I forget the torque value but it's high something in the region of 80-90 ftlbs. That's not the whole problem though it's the large surface area of the screw head that gets a grip on the top yoke. When it comes loose it will do so with a mighty crack. I used a quality Allen key with 4 ft of iron pipe on the end of it. I recommend removing the tank and padding anything that's likely to get hit if something snaps.

As for making it easier I'm not so sure what you could do. I doubt penetrating oil would get under the screw cap but you could try. There might be some differential expansion to be had if you froze the top yoke. Got to admit I just used brute force.

[Luca]

I also had trouble with that nut.  I used penetrating oil (got results after switching from PB to Liquid Wrench) and a regular allen wrench and a rubber or plastic hammer to whack on the wrench with.  It eventually shocked loose.

Now that I have a hand impact driver, I'd use that with an allen bit.  Hammering down on the nut could help break the thing free.  Though I didn't use an impact driver for it, hammering down also worked a treat on the threaded rings in the bottom of the fork stanchions.

[steve hawkins]

I dented the top of my tank the last time I had to remove it  So be careful.

Rev. Light

[montmil]

... Now that I have a hand impact driver, I'd use that with an allen bit.

I still have my impact driver set from the way-back days while working in a Honda shop in the early 60s. We were convinced that Soichiro Honda hired the offspring of Godzilla to torque those freakin' JIS case screws.

[Tony Smith]

I still have my impact driver set from the way-back days while working in a Honda shop in the early 60s. We were convinced that Soichiro Honda hired the offspring of Godzilla to torque those freakin' JIS case screws.

My circle of friends used to refer to them as "cheese headed screws" it wasn't that they were actually all that tight. it was just that an impact driver seemed to be the only thing that would break them free without deforming the screw head.
 
Mr Honda didn't realize it, but he spawned an industry, back in the day you bought your new Honda and then immediately began saving so you could buy the packet of stainless steel cap screws for your model. Funnily enough, one of the features that figured in my purchase of a Yamaha XS-750 was that they used cap screws from the factory. The first time I had to remove engine covers from the Yamaha was an absolute pleasure.