Head stock bearings question

WJBertrand

Ventura Highway
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Jun 20, 2015
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Thanks for all the info guys! Yeah the notch is VERY obvious with the bike on the center stand and just wobbling the handlebars a few degrees back and forth. It’ll settle into the notch as soon as you release the bars. Really weird to ride on grooved pavement.


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Boris

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midlands. UK
I’ve noticed over the past few ride outs, that there’s been a strange wandering at slow speed where the steering feels like it’s trying to centre, almost trying to follow a narrow rut that isn’t there. Got the front in the air a couple of days ago and there’s a definite notch at almost straight on.
I ordered the required C spanner for the grooved stem nuts and today started stripping the necessary bits off in order to inspect the bearings, hopefully tomorrow.
 

WJBertrand

Ventura Highway
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Your description of the steering feel is exactly the same as my bike’s symptoms. I just finished replacing my bearings a couple of hours ago. Still need to do some reassembly, but with the new parts the notch is definitely gone now.


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Boris

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I’ve noticed over the past few ride outs, that there’s been a strange wandering at slow speed where the steering feels like it’s trying to centre, almost trying to follow a narrow rut that isn’t there. Got the front in the air a couple of days ago and there’s a definite notch at almost straight on.
I ordered the required C spanner for the grooved stem nuts and today started stripping the necessary bits off in order to inspect the bearings, hopefully tomorrow.
Gen1 with just short of 39k miles.

Pulled it apart today, outer races seem fine, no cracks, pitting or noticeable grooves. Both bearings a little on the dry side. Bottom bearing a tad rough turning, even after regreasing, I guess the inner race isn’t great. New bearings ordered.

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Boris

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midlands. UK
New bearings arrived, which include the outer races. Old outer races came out easily, as there’s a groove in the headstock at 6 & 12 o’clock for both the top and bottom, couple of decent taps per side and out they came. New races in the freezer overnight, then used the old races to tap them in, no issues, went into place easily. Not sure if the freezer thing helps or not, but I had no fitting problems. Lower bearing on the steering stem went off to a bloke I know, he had to dremmel it off, said it was all a pita.

Got myself the proper grease, now just need to put it all together again.

BTW, it was the lower bearing that had failed causing the original problem.
 

WJBertrand

Ventura Highway
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I was surprised when I disassembled mine to find that there was plenty of grease in there. Obvious notches in the lower race. Yeah getting the lower bearing off the stem was a PITA. Destroyed the cage and sent the rollers all about the garage but finally got it done.


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WJBertrand

Ventura Highway
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BTW, it was the lower bearing that had failed causing the original problem.
Yeah, if you think about it all the weight is supported on the lower bearing so it's the one that takes the beating. I'm thinking one could repair this problem replacing only the lower bearing and race while just re-using the upper one. I think it'd be fine but since I was in there I just did them both.
 

Grizzly

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May 1, 2018
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Angus, Scotland
I was planning to strip and grease my head bearings this winter - but I've now noticed the dreaded notch - so I have now ordered new bearings and will change them out soon.

My question for you guys is ...... does anybody else think the "preload" suggested by Yamaha of 13ft/lbs is excessive???

I've changed quite a few sets of head bearings over the years - but my method would always be to preload the bearings initially to seat fully, then loosen off and re-tighten until bearings are just fully seated against their seats??
To tighten them down to a torque of 13ft/lb seems excessively tight for a pair of taper bearings - and will only encourage premature wear and notching in future??

Anybody else got any words of wisdom or thoughts on this?


Cheers........................Grizzly
 

teneleven

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Oct 15, 2021
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Ardenne
I was planning to strip and grease my head bearings this winter - but I've now noticed the dreaded notch - so I have now ordered new bearings and will change them out soon.

My question for you guys is ...... does anybody else think the "preload" suggested by Yamaha of 13ft/lbs is excessive???

I've changed quite a few sets of head bearings over the years - but my method would always be to preload the bearings initially to seat fully, then loosen off and re-tighten until bearings are just fully seated against their seats??
To tighten them down to a torque of 13ft/lb seems excessively tight for a pair of taper bearings - and will only encourage premature wear and notching in future??

Anybody else got any words of wisdom or thoughts on this?


Cheers........................Grizzly
I've also done it same as you on multiple headstocks and swingarms. Apply some torque on assembly to distribute the grease and center the bearings, then back it off 1/4 turn, finger-tighten it and lock. No pre-load.
 

WJBertrand

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I tighten just until all free play disappears and no more. I then re-check for any free play after a few hundred miles and tighten further if needed.


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RCinNC

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North Carolina
I'm comfortable doing it the way the service manual specifies, with the initial tightening to 38 ft/lbs, then loosening and re-tightening to 13 ft/lbs. I don't know why the engineers at Yamaha chose those torque values, but I presume there was a reason and they didn't just pull the torque values out of thin air. As to premature wear on the headset, I have 85,500 or so miles on my 2014 and I'm still on the original headset bearings (which don't have any issues), so I'm at least one data point in favor of the idea that following the SM doesn't result in premature headset bearing wear.
 

Grizzly

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Thanks for the replies,
Well job now done - and also changed the fork oil at the same time.
I ended up following my instinct regarding the head bearing pre-load. I know Yamaha engineers usually know what there doing - but not always!!!
I initially pe-loaded as per the workshop manual to seat everything fully - then slackened back and re-tightened to just touch down fully seated - not slack, but no pre-load - feels great.
Time will tell once road tested anf mileage increases but I can't help thinking the 13ft/lb is excessive. I can easily adjust later if necessary.

Cheers............Grizzly
 

ThaiXT

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Nov 16, 2022
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Thailand
The seals are attached to the bearings, and the bearings are different top and bottom. easy to knock out the outer but bottom one difficult to fit, I put mine in the freezer and gently warmed the frame, I ordered regular bearings and machined the seal to fit the new bearings so now very cheap to replace about £20 or 25 bucks, make sure you follow the torque settings to tighten, I had no tool so I 3D printed one that did the job, I might get some billet ones machined now. Sorry to be late on this post
 

RCinNC

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I finally had to replace the lower steering head bearing last July, at a little over 90,000 miles. I didn't have any sort of notch, but there was corrosion on the lower race.

The lower race was pretty easy to knock out using a piece of 5/16" steel rod I bought at the hardware store for a barbecue grill project. I put the lower race in the freezer the night before I did the work. Once I knocked the old race out, I used a Dremel tool and a diamond cutting wheel to cut a notch through the old race, and then used it as a driver to drive in the new race. I didn't need to heat up the headset tube; I just put a small amount of bearing grease on the outer surface of the race, and it went in with no issues.

The lower bearing was another story. I tried the chisel method, and that thing was not moving. Rather than start tearing at the bearing cage and trying to cut off the inner race, I took the steering head to the Yamaha shop and had them remove it. That was cheaper than buying the specialized tool for bearing removal.
 
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