Driveshaft Problem With Pic

[M5-]

Driveshaft Problem With Pic NEW THEORY ON BEARING FAILURES SEE BELOW

Hey guys

So I was doing some maintenance today replacing my driveshaft bearings and worn out jackshaft bearings and I discovered a problem. It looks like my chain case side driveshaft bearing has worn into the actual driveshaft. If you look at the pic you can see that the bearing race has worn down the driveshaft. So my first thought was that the bearing had seized but that was not the case. I have been pretty religious about greasing the bearings and they all had lots of grease in them and turned freely.

Another issue is that it looks like the bearing has been travelling back and forth on the drive shaft as the hex portion of the driveshaft is pounded as is the inner race of the bearing. Bottom line the driveshaft has worn down 15 thou and is fawked. Going onto the Timbersled's site I see they are out of stock on drive shafts so my question is "Is this a known problem and now WTF do I do"? I can put a new bearing on there but that isn't going to last.

M5

 

[portgrinder]

Green loctite and wait for a new one would be my plan.

Loctite 620 pretty sure

 

[Revv Up]

You could have the shaft machined undersized and have asleeve pressed on or find a bearing with a smaller ID and the same OD. Another option would be to have a machine shop weld it up and machine it back to stock specs.

 

[M5-]

I did think about having it spray welded then machined but it'll probably be as much as a new one. So this hasn't happened to anybody else?

M5

 

[M5-]

I did think about having it spray welded then machined but it'll probably be as much as a new one. So this hasn't happened to anybody else?

M5

 

[Jon Mutiger]

I can see how it happened, but it's never happened to me. Your lower sprocket bolt got loose, and you were walking left to right in the bearing. Your lucky in reality, it's still round and nothing let go. Green loctite, 638 is your friend in this case, it works wonders. The only problem is you'll probably never get it apart again without lots and lots of fire.

 

[Hawkster]

Check out the auto shops or even a transmission shop and ask for what some would call a speedy sleeve with the shaft size . use the green loctite on the speedy sleeve press on and also on the bearing .

 

[Rush44]

I can see how it happened, but it's never happened to me. Your lower sprocket bolt got loose, and you were walking left to right in the bearing. Your lucky in reality, it's still round and nothing let go. Green loctite, 638 is your friend in this case, it works wonders. The only problem is you'll probably never get it apart again without lots and lots of fire.

Jon is absolutely correct. When I went to replace my bearings today with Allen the exact same thing had happened to me. The cause of this is because my sprocket bolt was not tight enough and allowed the entire bearing to walk around on the drive shaft. The bearing was not spinning... the shaft was. It was so tight on there that we had to push the drive shaft out from the opposite side and put it in a press to pull the bearing out. It was really an eye opener as to how these bolts absolutely need to be red loctite and checked before every ride. If the entire unit isn't tight as a drum the kit and the bike will vibrate loose anything that isn't tight. It was quite a project but we were able to grind down the drive shaft and get it servicable again. What we did is we took the side of the drive shaft that the sprocket was on and actually flipped around to the other side so that the warn side was now on the non drive side. Also check to make sure that the shaft isn't bent and is rotating properly without a wobble. I thought that I was maintaining my equipment well enough and I was obviously very mistaken. Most of the issues people are having are attributed to a lack of maintenance and not design failure by Timbersled.

Tighten, locktite, grease. And don't forget to anti-sieze everything when it goes back together or you are in trouble when you try to pull it apart.

 

[summitboy]

Im pretty sure M5 bolts needed to be heated to be removed. Not loose. Ive see others have the same issue on the jackshaft. You can grease a bearing all you want but if the side load is just too much the bearing will destroy its self. The kit is just too flimsy and under bearinged imo. I guess thats why the new kits have the dual row bearings and are stiffer. The retro kit better be a decent deal !

 

[thnewell]

I sure hope that they have upgrade kits for a good price. I have learned enough just doing the maintenance in the first year to build a way better kit. I would way rather upgrade/build my own kit then give timbersled another 6k. I would pay for an upgrade kit if they were loyal enough and engineering allowed them to offer one.

 

[M5-]

I wish it was as simple as a loose bolt but this is the first time I have had these bolts or gears off since I bought the kit last fall and they were SUPER tight, I had to torch them and impact to get them off so IMO that's not the issue. I think they are eating themselves because of the flex in the side plate of the kit of course that's JMO. The bearings are done but they were a long way from failure, the bearings need to be the locking style with a collar much like Yamaha uses on their sled drive shafts which physically locks the inner race to the driveshaft. If I can run 300 hp through my sled track for a few seasons on the same bearings I should be able to run 50 HP on my bike and never even think about it.


M5

 

[dirtrebel]

Ive been running the self aligning type with eccentric locking collars on all my homemade kits with success. seems to cut down on the bearing spinning on the shaft problem. Although I guess karma is coming back to me, yesterday after 975 season to date miles the upper outer bearing took a crap and exploded! I told myself I was gonna replace all 4 if I made it thru hawkfest, but my buddy just bought a '13 sxf and longtrack kit and wanted to take it out yesterday, so I figured just one more ride, and boom! at the top of the hill at the furthest from the truck! I was able to limp it out 20 miles with the bearing completely gone, (I wasn't gonna make him tow me on his brand new bike in 3' of fresh powder, unless totally necessary) I think timbersled has a good product and it sounds like the new kits will be more ridged, however if u guys ride hard I would suggest replacing bearings 2 times a year, and immediately if u hit something. Just my .02 cents. Also if the problem is side loading do u think a double row bearing will be any better?

 

[dirtrebel]

also, m5 if I was u I would just go with the Loctite and be riding, its not gonna last as long, but just replace it again in a few weeks or months. If the speedy sleeve is not an option or turning the shaft around or other improvisational fixes aren't gonna work, another option is to use a lathe to knurl the shaft to work up some extra material to help regain a light press fit and then use the Loctite, some of my older kits had some pretty loose tolerances and lasted quite a while! good luck

 

[M5-]

Another issue I discovered is on the bearing that is next to the brake rotor there was no snap ring installed from new, as I haven't touched it, I assume its supposed to have one Yes? I'm going to try the Loctite as the spec on that 638 is right around 15 thou max.



M5

 

[stevie boy]

Cwooland can you take a snap shot of your home made kits. I need something to inspire me to build my own. I have a kx 500 that i was thinking about having some kind of perminate, ultimate fixture mounted to the bike. For some reason i was thinking how cool it would be to install my boss noss system for it to snort up its pipe.

 

[Rush44]

If you had to heat the head to get the bolt off then you were plenty tight. Mine were not (and neither was a group I rode with last week) and that was the cause of my troubles. I just want to make others aware that you just can't gas and ride these things week after week... you need to put in a little wrench time to keep everything in check.

 

[retired motoman]

Could have been worse.

Good thing you found it when you did. It happened to me a few years back but did not catch in time. So it was a long day on the mountain.

 

[dirtrebel]

here u go

Cwooland can you take a snap shot of your home made kits. I need something to inspire me to build my own. I have a kx 500 that i was thinking about having some kind of perminate, ultimate fixture mounted to the bike. For some reason i was thinking how cool it would be to install my boss noss system for it to snort up its pipe.

I sure don't want to hijack this thread so if u have any more questions maybe pm me, but since u asked here it is! I'm a super redneck but what the heck!

http://www.youtube.com/watch?v=JQRnWMiuEi0

 

[M5-]

NEW THEORY

So I have a theory as to why the bearings are failing. I replaced all my bearings and the 2 worst ones were the two on the chain case side, this is significant IMO. So when I took my bike apart I didn't have much adjustment left in my chain adjuster. I thought that my chain had stretched too much and was almost done. After I put it all back together the chain was really tight and the adjuster was just at the beginning of the range. What I think is happening and the reason my driveshaft is screwed is this.

When you assemble the kit and all the parts are relaxed you can align everything nicely and it all seems perfect. What happens IMO after you ride isn't that your chain keeps stretching what actually happens is that the chain case sprockets get pulled closer together till the bolts holding the bearing retainers hit the tunnel holes sides which results in the bearings coming out of alignment.

My bearings were full of grease with no rust or water but they were rough and ratcheting on the chain case side but the outboard bearings were fine. Because the holes that go through the tunnel sides and the holes in the bearing retainers are too big and have too much play there is too much movement. I get it that you need to be able to align everything but it can't be staying put which results in the bearings not running true. I don't think it's a coincidence that the chain case side takes the brunt of the punishment as they are the ones that will get the most out of alignment. I'm going to track the C to C on the sprockets and I'm betting it's going to drop, a lot.


Comments??


M5

 

[Hawkster]

A good belt drive