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Discussion in 'Thumpers' started by Drif10, Mar 9, 2005.
Thanks for the info.
I've always thought that it is probably the mainshaft getting pushed in and binding against the gears on the other transmission shaft. But I don't know.
This problem is why I think it's not a particularly good idea to use a puller than pushes on the mainshaft, although many have done this. Using a PVC pipe or some other fitting that goes over the mainshaft and pushes on the cases seems more prudent.
If your first thought was correct that shouldn't drif10 try opening up the other side and whacking the mainshaft back towards the new bearing? That might be worth a try before he splits the case or destroys the new bearing pulling it out.
Not sure what you mean about the second comment; pushing on the case would do what?
I think all you can get to from the other side is the countershaft which is, of course, a different shaft from the main shaft. If the binding is caused by the gears on the two shafts bearing on each other, then perhaps a whack on the countershaft would transfer load from one shaft to the other on the sides of the gears, but this sounds like it would be hard on the internals.
My first step would be to see if the binding is because the bearing is driven too deep. If it truly is driven well beyond flush, then there is no way you're going to be able to pull on the mainshaft or whack on it and pull the bearing back to the proper height. This sounds like at least destroying the new bearing to get a puller on it, or splitting the cases so it can be driven from the other side.
But if the new bearing appears to be at the proper depth, then perhaps the problem is just some kind of momentary binding of the mainshaft. In this case, I'd try and pull on the mainshaft, either by building a puller or using a slide hammer. You should be able to fashion some kind of puller that pulls on something held on by the clutch hub nut.
Any puller for the old ball bearing has to have something to push against to pull it out. There are two basic techniques: 1) push against the end of the mainshaft (this is what several commercial pullers do); 2) or push against the cases by putting a piece of pipe over the mainshaft that is slightly longer than the mainshaft and then having the pullers push gainst the pipe, thus transferring the loads directly to the engine cases surrounding the bearing.
I think the 2nd is much preferrable because the mainshaft probably isn't designed to take high loads on either end along the length of the shaft. This appears to be the root cause of these "binding" issues.
Thanks for the lesson mark - I hope drif10 gets sumpin' outa that too!
Just my .02 on some comments being made about the bearing pullers (pro & con)....
I don't think a puller that rests on the shaft should be any kind of a problem. The amount of force exerted to pull a bearing out can't be enough to jam up all the other parts/forces holding it in place. Especially if the bearing is in good shape.
Now if you drive the new bearing in with a sledge hammer or get it in at an angle, THAT would be a problem. But pulling the old one using the shaft end shouldn't cause any problems.
I haven't completed the bearing swap yet. May not. But even though I've seen some pretty creative pullers, I'll be going to my dealer or renting/borrowing one that's specifically made for the job. If I can trailer the bike down all set to go and pay the guy $40 to pull the bearing with the right tool, why go through all the hassle of fabricating a tool I might use once....
Again....just my .02
KTM does not recomend to pull the bearing using a puller resting on the mainshaft. KTM says you have to split the engine and change the bearing.
I just wonder if the fuck Drif is facing now may be the reason for this recomendation.
I don't know about this. I bent and twisted some pretty substantial pullers from Grade 8 steel and wailed away on some substantial slide hammers before mine finally gave up the ghost. If you look on the spec sheets for bearing pullers for this size of bearing, you'll see that the pullers are designed to apply up to several TONS of force. This is a lot of force being applied to that mainshaft that KTM never recommended be applied. It may work fine. It may not.
In thinking about this, there is no reason you couldn't use a commercial puller and still protect the mainshaft. Just build a cap over it that transfers loads to the case.
As Stefan said, there is no KTM puller "specifically made for the job." KTM says you should split the cases, heat the case halve in an oven, freeze the bearing, and press it in and out with a hydraulic press. The bearing is not terribly unusual, so commerical pullers like the SKF TMMD 61 look like they should work fine and appear to have been used successfully, but you're not going to roll up to your average KTM dealer with your LC4 in the back and expect them to whip out exactly the right tool to pull this thing. None of the dealers in my area had the slightest interest in doing this without splitting the cases for $1000 or so. Believe me, I would have gladly paid somebody $40 to yank this thing, but the option simply wasn't available.
None of my dealers even knew (know) about the potentially problematic bearing. They start blabbing about internet rumor bullshit. Same dealers that, when 6 months ago I said, "seems like there are gonna be some '05 ADV R's coming in" they said it would never happen.
Having pulled my hair out getting my bearing out, if you can find someone who will pull it for $100.00 or less (guarenteed work) I would say "Thats a bargin."
Odds are against it, and if you find a dealer that will do it, Post it here so we all know about it.
Glad you figured it out. May be the driving drift needs to have a larger diameter so you cannot drive the bearing past the case entry?
I used the old bearing to drive the new one in. I figured that it would keep it flat, and the old bearing would take the hit for my miscues. That worked out fine, it's just that I did not expect that the bearing could be driven too far in, thought that there was a seat for it, so I tapped the bearing in until it hit bottom.
Turns out that was the wrong idea.
Hey Flanny, was this the bearing that went on yours?
Just curious....is any Temp differential being used here, or are we just slammin' 'em home at room temp? I never replaced a ball or roller in my life in an engine where the cases weren't hot and the bearing wasn't intimately familiar with dry ice (OK, or at least a night in the freezer wrapped in a baggy.
Now I know we can't get things too hot if the motor is still together and we don't want the rest of the bearings to fall out, but an hour at 250 F is not really above running temp. And a little dry ice works magic on bearing OD's. What kind of interference are we looking at (Case Dia - Bearing Dia)?
You can force fit all sorts of stuff if you have an accurate press and the press-ee is well supported, but I see no future in hammering stuff in and out. Not meaning to be hyper-critical, you guys know a lot more about these engines than I do. But 20 years of design experience is screaming........wrong. It should not be possible to install a properly designed bearing too deep.
Glad to hear the good news. I've been following this thread closely. If it makes you feel any better, the frustration you had with the bearing is way less than if it had gone bad. Don't ask me how I know.
we got a big bottle of liquid nitrogen that works wonders in about 45 seconds.
Rose bud to the case might be a bit much but . works around the bearings I see. seen plenty of races grow .015/.020 thou with just a little heat.
Drif, you 'da man. I know the feeling.
We think the same way. Pity KTM don't!
On the temp difference thing -
Your driving on to both the shaft and the case, not a one at a time thing - so you cannot use the temp difference as heating the cases (with the shaft) and freezing the bearing will have the bearing bind on the shaft... catch 22. Nice try though.
Damn good point, Frank. It never occured to me because I have never tried to do both (install a bearing in the case, and over a shaft) at the same time before. It was always install the bearings in the case (shrink fit), and then install the shafts (light press fit). Live and learn.
PS - Maybe there is a reason I never tried for the daily double. Sounds like a job for a proper Hyd. press.
Humm lookin back at this 'lock ring' thingy.. is that possibly a taper fit inside the inner dia of the bearing? In that case you could do the temp difference thing ... but I don't think that is the case
I'd want a driver that pushes on both the inner and outer races ... with the outter much larger than the bearing to contact the case so as to stop the problem drift10 had...
To do both at once you'd heat the whole thing - keep the bearing at room tem. Then run the liquid nitrogen slowly over the shaft so that the remnates do not touch the case ... that would help .. but it aint prity nor safe.
time for a ride drif10?