Steering head bearings and assembly diagram

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Bucko
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Steering head bearings and assembly diagram

Post by Bucko » Mon Dec 29, 2014 5:48 pm

Hello , has anyone got a diagram showing the correct assembly for the steering head bearings , races etc . I know it sounds pretty straight forward but I reassembled mine in the order they came off the bike and it doesn't seem correct when I put it back together so im not sure that it was correct in the first place , the stem doesn't centre correctly in the top yoke unless I force it , that doesn't seem right ? The lower bearing is a tapered roller, the top a ball bearing , I have noticed some people fit tapered bearings both top and bottom , is this perhaps the problem as to why the stem is not centring correctly , im not 100% sure that the top bearing is the correct size for the headstock , it seems a little bit small for the outer race ?

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dicky
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Re: Steering head bearings and assembly diagram

Post by dicky » Mon Dec 29, 2014 11:44 pm

You should probably have both bearings the same type.
Original bearings were ball races, but now the Yamaha spare part bearing is a tapered roller. Same part number.
Don't know when they changed them over.
No Yamaha service manual that I know of shows the tapered rollers, only the ball races.
Removing the cup from the top of headstock is not a simple task, which may be why you have mis-matched bearings.
Perhaps both bearings were worn but only the bottom bearing was changed?
There is a thread on here somewhere showing discussing various ways to remove it. If you have a TIG it should be easy.
dicky
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alextrx850
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Re: Steering head bearings and assembly diagram

Post by alextrx850 » Tue Dec 30, 2014 2:45 am

dicky wrote:You should probably have both bearings the same type.
Original bearings were ball races, but now the Yamaha spare part bearing is a tapered roller. Same part number.
Don't know when they changed them over.
No Yamaha service manual that I know of shows the tapered rollers, only the ball races.
Removing the cup from the top of headstock is not a simple task, which may be why you have mis-matched bearings.
Perhaps both bearings were worn but only the bottom bearing was changed?
There is a thread on here somewhere showing discussing various ways to remove it. If you have a TIG it should be easy.
Right on it Dicky, the top bearing race is a right sod to tap up and out the top...theres no slot in the frame (like the lower ),to gain purchase...really need a mig welder to make a knob to tap it out.
That'd be why the top race is OEM .
Mind, the weight is on the lower bearing anyway.

Rich
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Re: Steering head bearings and assembly diagram

Post by Rich » Wed Dec 31, 2014 6:50 pm

If you have access to welder just run a ring of weld around the outer race. When it cools it will contract and the race will probably just lift out. Have a nice wet sponge ready to coll it off so you don't knacker the finish on the headstock.

I wouldn't mix taper and ball on the same shaft.

Bucko
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Re: Steering head bearings and assembly diagram

Post by Bucko » Tue Jan 06, 2015 9:12 pm

I have changed both top and bottom bearings and races for tapered rollered items , it wasn't too bad to get the old races out but a bit of heat definitely helped , the new races knocked in fairly easily after a night in the freezer.

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