2003 RX 1 Chaincase Bearings. Help Please!!!!!

[Len Todd]

Use the propane torch on the race and keep putting ice on the shaft. A little ice on the cover may help keep it cool. But you should not be putting much heat on the cover.

I would not use a puller as you could ruin the C-Clip "ridges" that holds the bearing/C-Clip in place. You also need to be carefull how much you pry, becasue of this.

I would bet that the reason that this particular bearing is going is because your jack-shaft is bent inside the chain-case area. Either that or you have had a run of bad bearings. At this point, I would stick to an OEM bearing.

Again, I would leave off belt and chain. I would make that jack-shaft turn freely before I put any power through it.

Good Luck!

 

[bgallant_7@hotmail.com]

Going to do just as you suggested today if I get the cover off and I will get back to you later in the day. Man if the shaft I bought is bent and the original too I am bending it around the machinist neck and the guy I bought it from. One thing I forgot to mention that came on me last evening while having a brain fart. The first winter I had the sled the brake rotor cut into the parking brake caliper due to the pads being gone and the spring loaded caliper coming out against the rotor. Any thoughts on this being a problem. Dial indicator should tell the tale right? Again thanks and I will let you know later how I progressed. Much appreciated.

 

[bgallant_7@hotmail.com]

Ok, all day at it and finally got the cover off. The inner race was welded hard. I used a dremel with the detail wand attached and a grind stone. Grinded a groove in the inner race then positioned the balls so they would fall out. Wore down three stones but got it. Now waiting to try the dial indicator. Even after the cover was removed the inner race would not come off, I had to keep grinding at it till it cracked, then I pulled it off with my fingers. A local guy from here told me that it sounds like the bearing is getting overloaded? How about the torquing pattern? Is there any certain way? And when the rotor cut into the parking brake caliper would that be an issue here?

 

[bgallant_7@hotmail.com]

Len Todd, I completed the dialing, here is what I got.
On the outer shaft, right on the outside edge, outside the cir clip, it read 0.06mm. On the shaft still, where the bearing is seated when chain case is assembled it read 0.04 to 0.05mm. I then dialed the rotor. The rotors edge gave three readings, they were 1.5mm, 2.5mm and finally 3.5mm. Then the face of the rotor dialed 0.04mm and 0.08mm. It seems to me to be obvious that the shaft is fine and the rotor is definitely in need of replacement, however I do not think this would be causing the bearing to go. Could it? I assembled the chain case last winter and installed the bottom gear wrong, it resulted the sled to have only reverse. I backed out of my driveway, hauled the rear of my sled around then backed it into the shed to fix my mistake. Now the rotor dialing the readings it did I would understand it doing damage at high rev or speed but to tear up a bearing in such a short distance and in reverse at that I'm lost. Any thought here at all now with those readings. Whats your thoughts of a bearing being overloaded and what exactly do this mean?

 

[Crewchief47]

Len, just for quick reference for you 0.05mm is equal to 0.0019" (about 2 thou, didn't know how much conversion you've done )

 

[Len Todd]

There is something odd with the rotor. I sounds like is has a wobble in it. I would need to see it, to say it is good. Also you had trouble with it before. I would replace it.

The jackshaft measurements seem like it would be O.K. for a sled with a number of miles on it. When you dialed the rotor and/or jack-shaft in, did you feel any resistance or hear any mashing/grinding. It should have turned freely. If it did not turn freely (i.e. without any resistance, or grinding noise) then you need to find the source of the resistance/noise.

Also, when the outer chain-case bearing went bad, is it is possible that you contaminated the oil with metal and possibly scarred the other bearings? For example: The inner chain-case jackshaft bearing. I know you replaced them all before. But could you have contaminated them this time? Maybe a good cleaning is in order.

Don’t forget to clean and oil up the bearings inside the idler and drive gears

Is it possible that the chain was ever cooked? I do not recall if you replaced it or not? If you have cooked it, it should be near it’s end of adjustment. If you are there with the adjustment, then the chain needs to be replaced.

Is it possible the oil seals got hot? If they have, it would be a good time to replace them.

At this point, I would be using a new OEM bearing. Not all bearings are made the same. They may be the same dimensions, etc. But, … I do not trust the cheap ones. Sometimes they work just fine. Sometimes they don’t. This is not a place to figure that out by trial and error. I typically save trial and error on bearings for the idler wheels, after I have already packed the old ones a few times

Now, … Put the case back together without the chain. Remove the belt. Put on the new brake rotor. Put on the brake caliper. Then by hand, turn the Jack-shaft. If you feel any resistance or hear any grinding, then you need to find the source of that resistance or noise. You may hear some bearing noise. But what you are listening for are increases of noise as you turn, rapidly by hand, the jack-shaft. If there is any resistance at all, you need to find it’s source.

If the entire jackshaft to brake rotor assembly turns freely and you have no variations of noise as you spin it rapidly, you should be good to put in the chain. As you reassemble, take your time. Speed Kilzzzzzz. Then, once you have it all back together, add your chain-case oil. Run it for 25-5o miles and then change the oil, when it is warm. Also, as you ride, that 50 miles, frequently check the chain case oil level and put your hand on the chain-case above/by the outer bearing. If it is getting hotter than the rest of the chain-case, you MAY need to watch this a bit longer or take off the chain and see where the resistance is coming from.

All this assumes you have all the right parts in the right order. When I get done with my jack-shaft, I only have a couple mils end-travel on the brake Rotor. If you have more end-travel on that Rotor, it is a good indicator of the need to go back to the exploded view drawings and check that all the parts are on that shaft.

Good luck. Please feel free to let me know how your testing, w/o the chain and belt go. I’ll keep a closer eye on the crackberry today.

 

[Sled Dog]

The chain must be too tight. No way a bearing should go that fast and it must not be getting lubricated enough.

 

[Len Todd]

Chain tension does bring into play something we have not talked about. But, he did get quite a few miles out of the second to the last bearing. Consequently, I assumed that he had chain tension adjustment down. But, you could be right. That is another adjustment that has to be right.

bgallant_7@hotmail.com - Do you have the info you need to get the chain tension adjustment correct?

 

[bgallant_7@hotmail.com]

Finger tight on the tensioner then tighten the lock nut right, that is what I have been doing. I clean the case entirely every time. I was at the sled just a while ago and dialed the shaft and rotor fully assembled and got the same readings from both. We spun the track and felt the cover as you mentioned above the bearing in the cover and it became very hot very fast. We dismantled the entire chain case and now have the case completely off and jack shaft out as well. Tomorrow I am going to the machine shop and having the shaft dialed in front of my own eyes to see. A local guy told me that the required 8.5 ounces of gear oil was too much and that i was getting pressure. The mechanic at the dealer told me this is not so as the case is vented thru the rubber on the dipstick. We felt no resistance or heard no noises at all when turning the shaft, just a little from the bearings as you mentioned. The oil had particles in it but I used new every time as well. The bearings you mentioned to oil, that is the ones with the needle rollers inside the gears correct, if so I oil them and roll the oil in before I install them into the case. I dialed the shaft and rotor with a naked case, with the gears in, and then with the chain in, then naked with the cover on then with gears and chain and cover on and all readings stayed the same. With concern to the chain tensioner I still have lots of thread left outside the case for adjustment, but with the chain being cooked I would not know. It feels pretty free when I clean it every time the bearing goes but if it was ever hot or not I don't know, it has no difference in color anywhere in it I know that. Tomorrow when I begin assembling I will be extra slow and cautious as to what parts are going where as to eliminate putting something in the wrong place. However I'm almost sure everything is correct, but I will be cautious and observant tomorrow. I' am also going to tighten the case side first tomorrow then the nut behind the secondary. Anything else please let me know, I will check the site later and before I begin assembling tomorrow. Again thanks for checking my topic and throwing things out there for me to do. Much appreciated.

 

[bgallant_7@hotmail.com]

When I mentioned we spun the track and the bearing got hot very fast I forgot to mention we had the motor turning the track but I guess you knew that, pretty hard to turn it by hand to make that bearing hot, lol, but just thought I would fill you in on that.

 

[Len Todd]

8 oz of chain-case oil is correct. This should show the oil level ~ in the middle of the double headed arrow on the STD side of the stick. Forget about the REVERSE side of the stick. There is a vent in the rubber on the stick. No pressure will build.

The bearings to pre-oil are the needle bearings. You are correct.

You are putting in a new unsealed bearing this time. Is that correct?

When you assemble it this time, I would leave the chain off and put on the cover and rotor, etc. If the jack shaft turns freely by hand then remove the cover and install the chain. You may want to tension the chain with the cover off to see how well it fits, how much adjustment you have left, etc. You do not want to spin it using the motor until later, when you have added the oil.

When you adjust the chain tension for the last time, I would tighten it finger tight and back it off ¼ turn. The reverse works better with some play in the chain and you will take unnecessary pressure off the bearings. The chain being too tight could have caused your first replacement bearing to fail sooner than expected.

Is this your very first chain? If this is the chain that went through all these problems, it is possible that it could be adding to vibrations causing pre-mature bearing failure. However, if there is a lot of adjustment left, I doubt it. But, I would lay the chain in both of the gears to see if the chain fits snuggly on the gears. I think you will be O.K. But it is one more thing to rule out.

I would be interested to know about the TIR after you take the jack-shaft into the shop. Given the measurements you have already taken, I think you will be O.K. But, it is one more thing to finally rule out as a potential problem.

Once you have it all back together and have the oil in it, then it is time to try it with the Engine. Again, I would be keeping a hand on the cover to see if it gets excessively hot. Watch out for the rotor. It will bite you, if you get too close. I would rev it a little and stop the track. Then put on the ol' paddy. Rev the thing up a little more. If it stays cool or uniformly warm as the rest of the cover, then take her for a spin. But, keep occasionally testing it with your hand for a while.

Use the exploded view drawings to verify every part is being installed correctly. Sometime I still have to go back to it. You can even use the ZOOM feature to blow the parts up in size to figure out the correct orientation. If you zoom in you can begin to see the discrete differences in one side or the other of some the parts, etc.

Watch that cover gasket. Often, the simple things get us. Make sure it stays put. Check the oil level frequently for the first 10-20 miles. Then after 50 miles, drain it through a rag and look for metal. Replace the oil and you should be good to go for a while.

Good luck!

 

[bgallant_7@hotmail.com]

Ok, I called the machinist and I was able to catch him before the shop closed. Totally forgot tomorrow was Saturday, duh!! Anyhow I have some great news, the problem is resolved, well I' am hoping and thinking so. Yes I used the yamaha open bearing this time. As I said I went to the machinist with the shaft and it was fine, it dialed 0.03 which the machinists assured me was definitely safe. I came home and started assembling the case. As you suggested I torqued the chain case side first and seen right away that less threads were visible after the nut was tightened on the top gear. I then dialed it and got the same readings every way as before. Fully assembled I ended up with 1.5 mils outside the brake rotor as to the measurement of 3.7 before. Another thing I noticed was when installing the cover I did not have to give it a little tap with the rubber mallet, the bearing in the cover used to be a little snug, even the yamaha bearing that blew was like it. I added the oil, 8 oz and started the motor and give the track a whiz. The cover stayed cool and the bearing held up. I then took the sled off my lift and went for a little spin, not too far but several rounds in the same track. Bearing was still fine and I kept feeling the cover and it was the same temp all over, luke warm so to say. Time will tell I guess, it was too late by the time I got this completed so I' am waiting till tomorrow to go for a longer ride and step up the throttle and see what happens. However in total tonight I put 6 kms on the bearing easy and it is still fine so that is why I' am hoping and thinking my problem is resolved. Could something so simple as 2mils too much shaft on the case side and the bearing not sitting in its right spot on the shaft give me this very prolonged problem? I will let you know how I make out on my longer ride tomorrow when I get back. Also thanks again for all the info you have passed along and the tips along the way, it is very appreciated and good to know that sites such as this one are out there. I will post you tomorrow.

 

[Crewchief47]

Is there a shoulder or step on the shaft that the bearing sits against? I haven't had one of these apart yet.

 

[bgallant_7@hotmail.com]

There is no shoulder visible there however the bearing goes on a lot easier now with less shaft, so I would think the shaft is slightly bigger beyond where the bearing is meant to seat. I put 30kms on the sled this morning and the bearing is still fine, case and cover all stayed the same temp, warm thats all, not even close to hot. I got back and drained the chain case oil and it had a bit of dirt so I filled again with new, going to do this a couple times to make sure I get all possible dirt out of my case. Also when shifting from reverse to forward I' am getting a little knock before the sled will engage, is this curable with a little tinkering at the adjustment arms on the reverse lever? Hopefully I finally have this solved. Give the sled some throttle and put 30kms on it so maybe I do have it. Fingers are still crossed. Bearing used to blow within minutes before and at low revs, so I' am thinking the problem was in the shaft being too long on the case side.

 

[Crewchief47]

Hmmmm, I wonder if there is a little taper in the shaft in that spot and it was causing the other bearings to be side loaded??? Would explain the short life. Wouldn't take much, even just a slight variation in Dia. would do it. Glad to see that you seem to be out of the woods.