GT250 head bearings

malloryman · Post by **malloryman** » Tue Feb 14, 2012 11:36 am

Hi all. new to the forum but can anyone help? I am restoring a GT250A 1977 and am having trouble with the steering head bearings.
I have fitted a set of tapered needle rollers from pyramid and the yokes now seem to be about 8mm further apart. I have checked the seating of the shells and bearings and both seem to be fine. - Any clues?

titan performance · Post by **titan performance** » Tue Feb 14, 2012 12:37 pm

You did take out all the old bearing?

malloryman · Post by **malloryman** » Tue Feb 14, 2012 2:38 pm

Yep. frame has been stripped and powder coated

titan performance · Post by **titan performance** » Tue Feb 14, 2012 3:29 pm

Wasn't being funny, but just wondered if you had forgotten to pop out the bottom halves of the old bearings.
Does the bottom yoke look to be the right clearance from the bottom of the headstock?

malloryman · Post by **malloryman** » Tue Feb 14, 2012 4:22 pm

no top nut hangs over

malloryman · Post by **malloryman** » Tue Feb 14, 2012 4:31 pm

sorry forgot to say the headlamp holder brackets also has too mch clearance between the yokes. could be the bottom bearing not correctly seated but it looks ok

saab9002 · Post by **saab9002** » Tue Mar 20, 2012 7:20 am

Hi, I've done the same and found the same problem, the reason for it is that a taper roller race is deeper than a ball bearing race, probably by about 3-4mm so that would work out about right(2 bearings = 8mm overall)

You could machine the inside of the top yolk to the dia+ 1mm probably 5-6mm deep which would make it closer to original and use the chrome rings and rubber sealson the bottom of the headlamp brackets from a 380 to make up the difference. If you want originality strip the bottom yolk off remove the new race and machine the yolk down then machine the top yolk to suit !

Chris

Suzukidave · Post by **Suzukidave** » Tue Mar 20, 2012 8:33 am

PEDRO wrote: don't even entertain the numpty idea of machining yokes stunningly dim idea

Pedro , you sure have a way with getting your point across

Suzukidave · Post by **Suzukidave** » Tue Mar 20, 2012 3:03 pm

I dont know about the 250's but some of the GT750 do need a step to be removed from the neck for the taper bearings to fit on viewtopic.php?f=9&t=5547" onclick="window.open(this.href);return false;

malloryman · Post by **malloryman** » Tue Mar 20, 2012 4:47 pm

Hi there all - Many thanks for all the info. I went back to my garage, stripped the whole thing down and looked carefully. The bearings I had from pyramid bearings had different depth of shell. I put the smaller one in the bottom, carefully built it and hey presto it worked ! Many thanks for all the help. No doubt i'll need more, I'm new to this restoration game.

GT250 head bearings

GT250 head bearings

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