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Bagstr

KTM Rear Wheel Bearing Service

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    Anyone else having trouble removing the steel spacers from the hub?  Seems to me, it would be a good idea to lube the seal interface.  The part pulled out on previous bikes and this '16 the fronts pull out. Wood dowel drift from other side?  Don't want to damage stuff.  Lube it first with lithium grease?   What do you recommend? 

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I'd put the axle in that spacer and wiggle the spacer out of the seal.

Usually the damn things are falling off when I'm trying to put on the wheel....

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I use a seal puller. If you don't have one, I highly recommend adding one to your tool set. They are less than $20 and make changing wheel bearings and counter shaft seals a breeze.

BTW, I just did the bearings on my 530EXC. You know the trick about putting the bearings in the freezer before installing, right?

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 Freezer , Yep. Also have seal puller but don't see that helping with spacer.   Thanks.    Tried axle to no success. Not changing the bearing, just lubing the seals.  Bearings are tight and smooth, just want to keep them that way.

 Getting help with brass drift tomorrow. 

 

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I bought some 1/2" dia brass rod and cut to various lengths. I have one that's 12" and works good for driving stuff out of the hub. Got the rod at IMS Kearny Mesa.

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On 12/5/2017 at 6:44 PM, Bagstr said:

 Freezer , Yep. Also have seal puller but don't see that helping with spacer.   Thanks.    Tried axle to no success. Not changing the bearing, just lubing the seals.  Bearings are tight and smooth, just want to keep them that way.

 Getting help with brass drift tomorrow. 

 

If it is working don't mess with it. My opinion. 

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16 minutes ago, kkug said:

If it is working don't mess with it. My opinion.

     Great Minds work in unison.   Ha!      Since I was riding Thursday, called off the surgery with the help of Charlie.  Didn't want to break something at the last minute. I imagine water has been in there causing some minor corrosion. 

Taking the wheel in for balancing to Grove Motorcycle anyway. They may be able to help me with the spacers.  Once the thing is greased, it should be easier.

      The Governor ; Taking it Easy

 Thanks for all the comments gang.  Also looking at the Tusk Blind Collet system for long-term solution. 

 

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The seal lips will wear grooves into the spacers. When they get the grooves they can be quite difficult to remove There are aftermarket spacers available with hardened bushings so they don't get the grooves. You should be able to get at the back side of them? Maybe No need for blind puller?

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Could also be fretting corrosion between the inner bearing race to spacer mating surface. Penetrating lubricant is always a good starting point.

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  Thanks again gents,

       Yes, sprayed inside with my favorite all purpose cleaning agent WD before re-assembling for Thursday. Also White Lithium on the outside grease seal. 

  Certain to cause calamitous failure soon.   Will throw it on the tire stand and try again to " Tap out " with wood or brass. This is my fourth KTM and never had this an issue.

          Bagstr, recently seen in the Anza Borrego 

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Bags -

You might want to consider replacing the bearings as well. KTM's are notorious for rear wheel bearing failures. I have witnessed the failure first hand and when they fail they can take out other components (hub, caliper, etc). I check mine regularly and replace at any hint of a problem. You may have to use considerable force to get the sleeves out which could put excessive lateral load on the inner races of the bearing. This is generally not something you want to do but of course in a case like yours there is likely no choice.

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   Follow-Up;   Showing signs of wear on the spacers.  Looks like a lack of lubrication in my opinion. At 5122 miles, it definitely needs more frequent attention... New spacers and grease seals in the near future.  The ash dowel moved one side, but needed a socket to push the second. Yes, I will get a collet slide hammer tool for more frequent access. Bearings show no slack.  https://www.motionpro.com/product/08-0292  There are cheaper kits, but I like the blue case.

  Who has an opinion on the best quality spacers,  All Balls, SKF or Pivot Works vs OEM etc. ?

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ZipTy racing is making some nice ones the front ones are combo alloy with hardened sleeves but are Yamaha style with plastic seal shrouds. the rears are combo alloy with hardened sleeves. they have beveled edges to aid in sliding the whell assy back into place. well thought out Ty design.

I was going to paste the link but doesn't work anymore.

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     Note the Reference to SKF Wheel Bearings.  I think to go this route and save by not buying the Motion Pro Collet tool.

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Couple observations:

SKF is a great brand, but you need to buy them as individual components- they don't offer a "kit" that includes the center spacer and seals.

He pulled the seal off the bearing to install it- at that point, many people say you should pack the bearings with waterproof grease. Bearings are a universal thing- rarely are they application-specific. They're sold by industry number and could be used for washing machines or something. The reason this is important is the quantity of grease is based on things like the RPM for which the bearing is designed. These bearings really don't spin very fast, and the theory behind packing more grease is to displace possible water incursion. Maybe yes, maybe no. But if you pull the seal (carefully, easy to damage) you might want to consider it.

The size of the driving socket is important- needs to be big enough to contact only the outer race, but still fit in the bearing boss. As he mentioned, don't hit the center race. Probably won't do any damage, but it's not cricket.

I was a little surprised at how he was smacking the seal around. Maybe these don't have metal bodies, but I always use an old seal on top of the new seal as a cushion so I'm not smacking the seal with a hammer.

I had to do this procedure once in a little motel in Utah, borrowing a little sledge from another guest and a big drift punch fromt eh Maytag Repairman.  And a tiny, yet important bit of help from CiD. The bearing kit Curtis brought me from Grand Junction used a slightly wider bearing, and because I didn't read the directions, I didn't know the bearing was wider than the recess for the circlip, which was supposed to be discarded. I was wacking that bearing trying to get it to seat before CiD (in a kind and grandfatherly tone) suggested read the directions.

Got it all squared away and back on the road the next morning. I broke down by noon that day (engine cam bearings)...I do not miss that bike.

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 Thinking about that tubular spacer at the center of the 80Nm of torque down the middle.  Swing-arm, shim spacer, inner race of bearing then spacer followed on opposite side by inner race, shim spacer, swing-arm. All needing exact dimension for brake etc. PMB, are you saying SKF Dimension is not accurate with stock tube spacer?  Or that your parts man gave you the wrong SKF part??  Inner race of stock and replacement would need to be matched for success with stock tube. 

Appreciate comments And will definitely be checking stock and replacement length.  Do not think Slavens sells the SKF tube, will check on that. Want to buy from him as he went to all the trouble to make a nice production. 

   Bagstr

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The bearing that Paul is referring to is an alternative and not the same as stock. You can get SKF bearings that are the same as stock. I always pop out the dust seals (carefully) and wash the grease out with solvent. Then repack with a generous amount of waterproof grease and re-install the seals. You would be surprised how little grease is in them. I use a long brass drift from the back side to drive out the old bearings since I am not re-using them.

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Randy is correct.

The kit I bought was an aftermarket "upgrade" and I'm not even sure they were SKS, and I apaulogize for the confusion. In either case (SKS or aftermarket) the spacer is the same- stock.

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Here is an obscure tidbit (below). Partially retained from tribology classes and confirmed on the internet. Too little or too much grease is critical in machinery lubrication where high speed, high load is seen, and down time is bad. Probably not a big deal on motorcycle wheels. On bikes they are cheap and easy to replace. I carry one spare rear wheel bearing with me. "Usually" only one craps out first. On second thought...maybe I'll throw that other one in the pack too.

From SKF:

G = 0.114 x D x B

Where G = the amount of grease in ounces

D = the outside diameter of the bearing in inches

B = the bearing width in inches

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 Then -  Only need .10 grease x area of greased area .

     Gotta Plan heading to Execution.    Thank You Gentlemen!   

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4 hours ago, amgems said:

From SKF:

G = 0.114 x D x B

Where G = the amount of grease in ounces

D = the outside diameter of the bearing in inches

B = the bearing width in inches

Interesting- no factor for RPM, temperature, load, or run time, just a constant quantity based only on surface area. Same quantity for ball or roller as well?

Huh.

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In reality the only downside to over greasing is that the seals may pop and it will sling grease\let dirt in. I pack them liberally but leave some space for expansion, etc. Never had any issue. These are primarily electric motor bearings designed for higher rpm (1750 rpm for most induction motors) and relatively low loading. On a dirtbike it's the opposite - lower rpm and high impact loading. 

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2 minutes ago, paulmbowers said:

Interesting- no factor for RPM, temperature, load, or run time, just a constant quantity based only on surface area. Same quantity for ball or roller as well?

Huh.

From what I rember ball and roller are the same. Roller would get more because they are wider. Type of grease is important too. With synthetic the frequency would be less. High temp would use special grease.

Here's the web page I found that kinda confirmed what I think I thought I remembered: http://www.machinerylubrication.com/Read/28664/dangers-of-overgreasing

All this is probably overkill for motorcycle wheel bearings

They say this further down the page.

"After you have determined the correct volume, it’s time to establish the proper frequency. There are several methods for estimating a regreasing frequency, including multiple calculators, tables and charts. The major factors in determining frequency are load, operation time, type of bearing, speed, temperature and environment."

 

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