Steering Head Bearings Problem?

[squirrel_hunter]

Got a slight issue with the steering head bearings on my TZR250 2MA Project.

I've installed the races into the frame, the upper sits a bit high and the races don't go over recess like the old ones (or like the ones I replaced on my SV) so removing them looks like it might be interesting, though I'm not worried about the height.

Lower:



Upper:



I had a local garage press the oil seal, bearing dust seal, and then bearing onto the lower yoke:



But after assembling the yoke its very stiff to move. It would appear that the dust seal is grabbing the bearing once under a bit of load.

So quick chat to the bike shop and we removed the oil seal. Trouble is its still stiff and when losing the bearing off I found a bit of grey powder on the top which implies that it is rubbing on the frame recess?

The only thing I haven't done yet is fully grease it up as I don't want to end up masking any issues with it. So should I apply lots of grease to it and see what happens or can anyone make any other suggestions as I'm a little stuck on this one?

[Bibio]

did you buy an OEM dust seal or buy taper rollers with integrated dust seal or taper rollers with loose dust seal?

[squirrel_hunter]

All pattern parts. All from Yambits. Seal, Bearing Kit.

The tapered roller bearings came with separate dust seals. Both dust seals carried the same part numbers on their packets so I expect them to be the same size.

Are the bearings the same diameter and thickness?
It's hard to tell from the picture, but, could you have the upper and lower bearings reversed? If they are the same, that couldn't be a problem.

[Bibio]

just from the picture the seal look a bit big. are you sure its the right way round?

[squirrel_hunter]

The upper and lower bearings are different sizes. I'm sure I have them round the right way as the upper bearing will not fit down far enough over the stem to seat. The outer races are also correct. I only opened one of the bearing packets and fitted that fully before opening the upper.

The bearing dust seals are round the correct way from what I can tell as the edge of the seal cups the bearing. If it didn't the seal would flatten its lip when installed which wouldn't be right.

I've done a little more checking and the top of the lower bearing is touching the frame recess over the top of the outer race when installed. I've taken a couple of photos and the one without the flash shows up the best. You should hopefully be able to see a polished edge off of the lower race on the frame.



So it looks like I have two issues, one the dust seal is gripping the bearing. And two the bearing is rubbing on the frame. Where do I go from here?

[Bibio]

if the bearings are touching then you will have to remove some of the material in the headstock, which means taking the races out again. did the parts come in official Yamaha packaging?

[squirrel_hunter]

No the parts are pattern replacements.

Not sure about modifying the frame. Would hope that there is something less drastic that could be done.

Alternatively I suppose I could refit new OEM bearings which as loose balls in a race?

You could shim under the lower outer race, but it would take a precision washer of the correct i.d. and o.d.
I wouldn't hesitate to take a rotary file to the offending extra material...

I was still thinking about the differences in the upper and lower bearings. Obviously the i.d. of the upper is smaller, but, could the outer races be reversed? Will either roller assy. fit in either outer race? Will either outer race fit in either bore?
I'm guessing the lower bearing assy. is more robust than the upper- does that apply to the outer races?

[Bibio]

take a die grinder to it. those races are in for good so as long as your careful you should be able to save the day. if not then remember to put checks in when your grinding the excess so you can get the next set out if need be.

once its all fitting then grease grease grease. there is a proper way to pack taper bearings with grease.