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2010 YZ450f Steering Column Bearings


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So tonight I decided to tack apart my triple clamps, linkage and swingarm to regrease everything as I havent since purchase. Upon a first look the triple clamps bearings looked fine, a little dirty, but fine. I cleaned everything and used Lucas oils xtra heavy duty wheel bearing grease to lube everything. I put it back together and lightly tightened the lock nut below the top clamp. Then assembled everything and torqued the head bolt to 100 f lbs since the manual calls for 105. My steering seams really stiff, not free at all like I presume it should feel like. Is there a special technique to tightening the locknut below the topclamp, or are my bearings shot. Its a 2010 and I couldnt find anything wrong with the bearings. Maybe since they were repacked it filled the slop and feels like that. How do you guys tighten that locknut because it says 5 ft lbs but i only have a punch and hammer. Are replacing these bearings necessary every year?

Edited by skullcandy
forgot to put the year
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The torque on the bottom bolt is not very much, tightening this bolt any tighter will make your bars turn rough. It's not designed to be this tight at all.

What I do is tighten the bottom bolt just enough so that when I turn the front wheel it feels very smooth and there is no up and down play in the steering stem. I use a clutch holding tool to grab the nut, it works very well. Afterwords I put the upper clamp on and then tighten that bolt to 100ft pounds, this upper bolt should not affect the steering in any way if you tightened the lower bolt properly.

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in the past, the way to measure tension on the bearing was to make it tight enough to allow the front to flip flop in slow motion on a center stand, when pushed to the side.

But I remember where some of the pro teams now make it tighter to bind a bit, and claim

it acts as somewhat of a stearing damper this way.

I tried the second way and it actually works.

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How do you guys tighten that locknut because it says 5 ft lbs but i only have a punch and hammer. Are replacing these bearings necessary every year?
Bearings are replaced on an "as needed" basis, and except for installing the upgraded upper bearing in my '06, they haven't been needed.

The bearing preload ring nut I usually torque by angle and/or feel with a big pair of pliers. First, tighten it to around 20 ft/lb, and rotate the stem several times. Back the torque off just to the zero point, where there is no slack, but no torque on the nut, either. Then turn the nut 1/6 turn tighter using the notches as a reference. That should do it for you.

When the ring is tightened, the pressure pushes the nut up in the stem threads. When you install the top clamp and torque the crown nut, that pushes the ring nut down in the stem threads, tightening the bearing load. If it seems tighter or looser than you like, make an adjustment. The baseline is where the bearings are just tight enough to hold the fork in any position with the front wheel removed.

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I had to replace the bearings in my 2010 450 due to moisture. At brand new I took the steering off and greased the bearings and at 30hrs I was going to clean them and repack em when i noticed a notchy feeling when I would turn the bars(knowing they were shot).

After taking the clamps off i seen moisture in the bearings. took the top bearing out and noticed it had some rust on a few rollers and the race had some shadowing and a small hairline crack in it. the bottom race looked ok but after cleaning the bottom bearing and letting it dry they didnt roll good so I just decided to replace them as well.

I tightened my ring nut to about 20lbs cause when I got to that point it felt like the nut was going to strip so i just stoped(even though the book called for like 27lbs) and then backed the nut off about a whole turn and then tightened mine to 8 lbs.

I keep my bike down in the basement so I guess I will have to run the dehumidifier in the winter as well.

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as for the wrench,i figured you would be one to use the proper tool intended.

Oooh... ?

When the "proper" tools clearly do a better job of it, I do, thus I own real fork seal drivers and flywheel pullers. When the "proper" tool is not clearly superior to other methods, I consider them a waste of money and move on.

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Was it 06? I thought it was 05, at least for the two strokes when they changed the seal design...

On my 05 yz250 I greased them once, checked them after the season and they were still in excellent condition..

Nope. The upper seal and the bearing has been the same for I don't know how long, but at least through the years '02 through '08 and beyond. The frame is what changed, and I don't know about the two stroke frames, but the YZF's had a significant problem with water intrusion into the head bearings.

Sometime during the early '07 model year, a revised upper bearing that included a built-in seal was introduced as a service part, and I believe it finally went into production bikes in late '08 (not certain). When you try to buy the original 93332-00068-00 upper bearing at a Yamaha dealer, the counter terminal will change the number up to 93332-00078-00 automatically, and you'll have the new one. Insist on the 78 if they try to dell you an old 68 form shelf stock.

Also, check the external seal over the bearing. No idea why, but it seems almost all of them on aluminum frames have a cut in the lip.

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Oooh... ?

When the "proper" tools clearly do a better job of it, I do, thus I own real fork seal drivers and flywheel pullers. When the "proper" tool is not clearly superior to other methods, I consider them a waste of money and move on.

just for FYI for everyone the proper tool is 70 bucks and just a 1/4" flat piece of aluminum cut out to fit the ring nut and a 1/2" ratchet (waste of money). I've got one somewhere but haven't ever used it.

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Just an update. I decided to build a tool at work for adjusting that locknut. I just took a piece of 1" pipe and cut in to 6 inches in length. Then took the nut and marked the bottom piece of the pipe. I knotched the marks out so the pipe fits perfectly over the nut then welded a flat washer and 3/4 nut to the end. Cleaned it up with a wire wheel and it works perfectly. Fits over the steam perfect and torques good. A little heavy but now my stearing is smooth as butter.

Chow

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As yall know I stated earlier in this thread that I replaced the upper and lower bearings in 2010 450 a couple weeks ago.

I preloaded the bearings to 20ft lbs and then backed the nut off about a whole turn and then took my ring-nut tool and attached my torque wrench(beam type) to my ring-nut tool.

I then torqued the nut to about 8lbs and thought that would be enough. i went riding this past sunday (first ride since late october) and fell over around a turn that was and had a lot of ruts in it.

The outcome of the fall resulted in my Flexx handlebars being pushed to the right to much(out of line). So I took the tire back off and the bars and top clamp and loosened the ring-nut back off.

I lined the lower clamp back straight and then tightened the ring-nut to 15lbs.

It feels a little stiffer when turning the bars now but I dont think I tightened it to much more than what I had it (7 more ft pounds).

Will there be a problem that will arise in the future with me of tightening the ring-nut to 15lbs?

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I don't think you'll have any problem with bearing life as long as they stay clean and well lubed. I don't agree with setting the bearing that tight to have them serve as a friction type steering damper, though, because I think the negatives outweigh any advantage.

But from the standpoint of just the bearings, tapered roller bearings actually lass longer in almost every application when they are preloaded than when they have clearance because the rollers never impact the races. Running the head bearings with any slack in them would quickly destroy them. The design tolerates preload exceptionally well, too. A lot of automotive applications using TR bearings that run under heavy loads at high speeds call for high levels of preload.

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Well if you dont mind me asking,which nut is responseable for keeping the handlebars in a straight path......The ring-nut or the top nut?

Or better yet........ When a fall occurs,what causes the handlebars to twist to the left or right? would it be the ring-nut not tight enough?

The ring-nut is what I'm thinking ........Thats why I sinched it up a tad.

I checked the movement of my bars awhileago and it seems smooth when pushing it side to side. It is a little stiffer than before but not a whole lot.

If I turn the bars to the left(clutch lever side) there is no slop and the the steering will stop on its own and not fall own its own.

Before I tightened the ring-nut down some more my handlebar would fall to the left on its on when pushed in that direction thats why i tightened it up some more to prevent the handlebar from getting out of align when a wreck occured.

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Well if you dont mind me asking,which nut is responseable for keeping the handlebars in a straight path......The ring-nut or the top nut?

Or better yet........ When a fall occurs,what causes the handlebars to twist to the left or right? would it be the ring-nut not tight enough?

The nut that sits behind the bars on the seat.

None of the items you listed are responsible for keeping the bars straight in a crash. Plus, you've overlooked the bar mounts, which, if they are two separate clamps not connected by a bridge, can twist in opposite directions on the bars. This is even more true of bar clamps mounted to the clamps in rubber isolators.

The most important thing keeping the forks from twisting in the clamps is the pinch bolts on the upper tubes, but you CANNOT take the step of trying to stiffen things by torquing those beyond specifications. The ring nut on the steering head is there for the single purpose of setting the preload on the head bearings and providing a stop against which the crown nut can be tightened. With the crown nut tightened against the ring nut, the only binding force it provides that would resist it rotating on the stem is the clamping effect of 105 pounds of torque against the stem threads.

I recommend not crashing so much, or at least stop being surprised that something gets knock out of kilter.

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I'll ask you this and leave ya alone. What part do you think gets out of adjustment to where you .........(like when you wreck or fall over and your bars are to the left or right to much) have to get in front of the bike and put your knees on each side of the front tire and reach up and grab the handle bars and turn them in the opposite direction in what you are turning the wheel in.

Since you mentioned it above I believe its the handle bar clamp (without the bridge type) that may get turned in one direction which cause's the bar to get out of alignment from the front fender or wheel.

BTW I have never had any problems with the forks twisting in the clamps even at the specified torque setting of 23ft lbs. I never over tighten the clamp pinch bolts.

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What part do you think gets out of adjustment to where you .........(like when you wreck or fall over and your bars are to the left or right to much) have to get in front of the bike and put your knees on each side of the front tire and reach up and grab the handle bars and turn them in the opposite direction in what you are turning the wheel in.
Most often, it's the forks that slip in the clamps slightly, and loosening the upper or lower pinch bolts usually lets them "spring back" to where they belong. Sometimes it's the bar clamps, and sometimes it's both.

BTW, triple clamp pinch bolt torque on your bike is spec'd at 15 ft/lb, upper and lower. It was 17/14 on the '06.

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