Stub shaft Bearing behind clutch noise?

[NorthernMainer]

Haven't rode my sled in a few weeks (2014 Nytro, 3500 miles). Went to take a ride to town, and noticed there is noise coming from the primary clutch area. Talked to my buddy who used to own it, he said its the gear reduction behind the clutch, and it's normal... but how loud should it be? I can hear it pretty good when I am going slow.

 

[Sevey]

I don't know about the gear reduction, but the pto shaft (primary clutch is mounted to it ) is supported by a sealed bearing that does not get any lubrication from the engine. If it is higher pitch sound the bearing may be going out of it. If you are over 20,000km start paying attention to it. I had mine off this summer and the bearing did not look that healthy - mileage was 17,000km at the time.
When it goes, its a 'show stopper'.
MS

 

[STAIN]

there is no gear reduction on the 3 cylinder engines, only the 4 cylinder.

 

[STAIN]

I don't know about the gear reduction, but the pto shaft (primary clutch is mounted to it ) is supported by a sealed bearing that does not get any lubrication from the engine. If it is higher pitch sound the bearing may be going out of it. If you are over 20,000km start paying attention to it. I had mine off this summer and the bearing did not look that healthy - mileage was 17,000km at the time.
When it goes, its a 'show stopper'.
MS

Was that bearing easy to change? Is it just a bolt on? The bearings seem pretty cheap. Maybe a maintenance item?

 

[YukonMP]

Gear reduction on the Genesis 80 also. That is the 500cc tw0 cylinder in Phazers and Venture MP or Lite.

 

[shadow44]

Search "clutch rattle" and you'll find a lengthy but very detailed thread that explanes the noise.

 

[NorthernMainer]

It's not clutch rattle, it's bearing noise. Yamaha's are famous for clutch rattle. This sounds nothing like it.

 

[Pries]

When you pull the stub shaft out, you can replace the bearing at that time. My '08 Nytro used a 6307 2RS sealed bearing which I replaced while I had it out. Be careful with the seal behind the bearing though as if you damage it, they are not available separately ;-)

 

[NorthernMainer]

Well I will buy a clutch puller, and check it out! I just don't want to damage anything. To me, something just does not sound right. It's a bearing/whining noise.

 

[Pries]

You may want to refer to this thread for the details. http://ty4stroke.com/threads/official-clutch-rattle-removal-thread-w-pics.114990/

 

[Mills]

Your primary clutch is bolted to a stub shaft assembly. Yamaha did this to take the load from the clutch off the crank and crank bearings because four stroke engines cannot handle the load. The noise you are hearing is coming from the large diameter bearing behind the stub shaft cover plate. I had to replace mine at about 5,000 miles. I have the proper tools and/or made the tools to press the bearing out and the new one in. If you do not have a hydraulic press and tools I would suggest taking the stub shaft assembly off and then take it to a machine shop or your dealer to have the press the old bearing out and the new one in. You will have to unbolt the crank trigger sensor are raise it up slightly before you pull the stub shaft assembly out. Also, the input side of the stub shaft and the end of the crank are splined to match. There is an index spline on both to get the crank trigger marker on the stub shaft to line up to the engine properly. Make sure you have those two spline lined up properly when you are putting it back together.

 

[STAIN]

I see people have tried to Loctite these splines, not sure if this is a great idea. Has anyone just put some grease on the spines to quiet them? We used to permatex output shaft splines on drive shafts to quiet some noises in trucks. I just ordered that bearing today and am going to change it for maintenance purposes. It is pretty cheap.

 

[Pries]

I see people have tried to Loctite these splines, not sure if this is a great idea. Has anyone just put some grease on the spines to quiet them? We used to permatex output shaft splines on drive shafts to quiet some noises in trucks. I just ordered that bearing today and am going to change it for maintenance purposes. It is pretty cheap.

The loctite that is used is the one for slip fit bearing retainment...you can still pull the stubshaft off.

 

[Mills]

Belzona for repairing damaged steel shafts would probably work.

 

[Sevey]

Was that bearing easy to change? Is it just a bolt on? The bearings seem pretty cheap. Maybe a maintenance item?

Hey Stain,
Now that I have done it - I could do the next one pretty quick. Had a couple hic ups but got it together. Like the earlier comment you will need a shop press and some plates to get in there to press things out. I even had a specific dia pipe cut to press the bearing out.

The shaft assembly came out with a slide hammer puller. Remove clutch, take the 4 bolts out, heat the outer ring up with a heat gun, apply really good penetrating oil. I attached the puller with the clutch bolt. And gently used the slide hammer to pull it out. Heat helped a lot. The inner ring on the shaft assembly is prone to rust, so it can be sticky.

As for the bearing - I thought I would find a bearing from another source but ended ordering through Yamaha. In the 2012 microfiche, that bearing is an individual part no. Previous model years, it is all one assembly and very expensive. I would be careful using another bearing. Many are not rated for the rpm's and heat. I would stick with the Koyo.
Hope that helps.
MS