Drive shaft bearing...09 Nytro xtx

[gitrdun]

I suspect that you have the impenetrable NTN bearing available in Canada(sold by Yamaha dealer). Originally it probably was a serviceable NSK bearing from the factory, but since your New Brunswick dealer serviced it, you now have an unserviceable one. If you want a serviceable NSK, you may have to order from U.S. such as Portyamaha. Same part number.

 

[gitrdun]

 

[mp5]

Yessir...thats the one I want. Thanks again man!!

 

[porkchop]

Both of my '09 just went down to Excell's for replacement- one has 6k, other 4k.
More wear item preventive maintenance.

 

[mp5]

Found the serviceable NTN bearing. Identical PN to Yamaha one. I installed it, and good to go. Now I have the skid out and going over that. Ended up ordering all new bearings for that as well. Only two were beyond repacking, but might as well replace all while I have it out...and will be good for another few years. I think I'm going to start cleaning and repacking all my skid bearings in the spring so water doesn't sit in there all summer and cause the rust damage. Also thinking of ordering the STAR Kit while I'm at it...I've only read good things about it the last 3-4 years.

 

[Sevey]

Its amazing how long all those skid bearings will last if they are fully cleaned out, and repacked.
Still on the same bearings for the 3rd season. All in great shape.
MS

 

[porkchop]

Before storage I clean them using a degreaser / water then spray most of the sled with a couple cans of WD-40.
Always try getting some in around the idler wheel bearings, shock shafts, piviot points- haven't had a lot of seizing up.
Bought a bulk lot of like 12 6005-2rs bearings from JSB on ebay, not sure of the brand but they've held up ok for the price. Couple seasons maybe, easy wear item to replace.

 

[Sevey]

When taking my drive bearing off this summer I noticed that the shaft became loose in the bearing and had been turning. A small groove was carved in the shaft. Yes the set screws were tight, but obviously not tight enough. Never had seen this before.

Was thinking of changing the set screw so it has better bite on that shaft. Has anyone had this issue, and had to come up with a fix?

My only ideas at this point are:
1) change set screw with concave end so it bites better on the shaft.
2) try and replace the whole thing with a small bolt where I can possibly get a socket on it and tighten it more.

 

[mp5]

Do you dab any loctite on those set screws?

 

[Sevey]

yes. Always have used red and turned that allen head set screw as tight as possible. On prior removals you could see dimples in the shaft in that spot from previous installs. Now there is a smooth grooved ring.
The end of the set screw has a really smooth dimple that I am wondering at this point will not have enough bite.
MS

 

[nickleuci]

[I searched all through my service manual for that part and could not find it. It wasn't in the track section or the engine section..]
I am guessing you haven't noticed the parts finder button on the top right corner of this page.

Well now. I learned something today [emoji106]


Sent from my iPhone using Tapatalk

 

[gitrdun]

What condition was the bearing in to have enough resistance to cause the collar to spin on the shaft and make a groove? Did you replace the bearing and set screws? Here are Yamaha Canada's bearing and set screw, and in the red box is Yamaha USA bearing and set screw. I prefer Yamaha USA bearing because it has a serviceable seal, and I prefer the Yamaha USA set screw because I suspect it has a better bite. The Canada set screw looks like it has a ball bearing on the end, and the USA has the concave end.

 

[Sevey]

It was the Yamaha NTN bearing with the rigid seal.
Replaced it this fall and the old one was not in bad shape (could easily handled another 2-3,000 kms), but since it had high km's, new one was installed. So it had nothing to do with bearing condition.
Clearly I had something to do with it, but need to stop this now before a new drive shaft is in my future.

I am looking into replacing the set screw with a bolt, that has a bigger allen head and a concave end to bite into the shaft better. Even thinking of drilling a small pilot hole in the shaft so the bolt can sink into the shaft a bit deeper.
Any thoughts?
MS

 

[gitrdun]

I am curious to know which set screw you are using. But regardless, I would think that if you used a couple of new set screws of the USA type, torqued to 6.5 ft. lbs., I would expect it to hold. I would not grease the shaft where the set screws make contact. I am no expert, but I would be hesitant to drill any holes. You could mark the location of your set screw on the shaft with a paint pen and check it every now and then to see if it has moved. I would try that first.

 

[Sevey]

This is a stock bearing from Yamaha. It is the one with the seal that should not be removed. i think the set screws are larger than the other type of bearing available - 6mm x 0.7. I think I am going to put a set screw in that has a concave end instead of the nipple set screws. I have to believe they will bit that shaft better.

I have been thinking about the 'grease' comment. I rebuild things well greased but in this case; that bearing and shaft likely should go together somewhat dry so they bind together. I noticed on the SW forum they are having problems with this bearing and Cannondale has used acetone to etch the surfaces so they corrode together to bind and wont slip.

Good idea on marking the shaft.
Thanks for the help
MS