Long story short first time out on our recently purchased KFX 80. Runs great but I hear a very distinct grinding noise only when wheels turning. check oil in tranny, grease rear end, put chain tensioner kit on but still the noise.


Completely rebuild clutch and variator with new rollers and such.

Put back together still the noise.


I am working on isolating the noise but I have a bad feeling it is coming from the counter shaft or drive shaft box.

Is this a big project and is there something that is a normal failure on this bike.

With the time it takes to get parts I am getting worried that I may have to cancel my next trip if I have to keep guessing until I find the problem.


Thanks in advance.

 

Gears have been known to break/strip/etc.
Not a common problem but it happens.
Get it up in the air and turn the rear wheels and see if you can tell if it's in the gearbox or rear end. (like you didn't know that)LOL
I have transmision gears here if need be.

 

Thanks,

I'm in the middle of isolating the noise now. I have it off the ground and will disconnect one component at a time until I get rid of the noise.

What special tools do I need to tear into the gearbox?

Seal puller or bearing pullers?

 

A impact wrench will help get the clutch nuts off.
I think once you are into the clutchs we'll learn alot.
It could be the rear clutch shoes, Rear clutch bearings. If not you take the gearbox cover off.
What you'll need: 5mm allen wrench, 8mm socket, 10mm socket, 17mm socket, impack wrench, screwdriver and matching hammer <G>, maybe some neosporin and a bandage for a cpl skinned knuckles.

 

Thanks LT80, I know you help alot of people and it's appreciated.


I have already completely rebuilt the entire clutch and variator per my first post. Replaced rollers, faces, the whole shot. I am certain it is not a clutch issue.

I am going to start by removing the chain and reving it up. If noise stops it's most likely an axle bearing.

Next I will remove belt, if the noise stops it's likely the clutch or final drive and just rebuilding the clutch I am certain it is not that.

If the noise is still there it has to be a crank bearing

Just curios what I need tool wise to get into the final gears without destroying something. I have a good supply of tools but don't have a seal puller

 

Sorry, I didn't look back.
Remove the gearbox cover bolts. Pry up on the cover. Make sure you apply pressure to the input shaft so it stays in place.
If you end up taking all the gears out, remove the 2 bolts that are behind the front sprocket and use a hammer and bump the splined gear.

 

Well after eliminating the possibilities one by one I have narrowed it down to the carrier bearings. Got the axle out but can't figure out a good way to get the bearings out.

Glad I didn't have to tear into the final drive

 

After removing the housing: Alot of cleaning then alot of heat. It's not a easy process.
I think I have brgs and seals here that I'd give you a deal on if needed.

 

Thanks LT

I am a little confused though as there is a very very small lip on the inside that you can use to bang them out from the opposite side.

I will try a long extension with a socket that close to the outer diameter but small enough to get in there.


Then I assume I just heat up the outer carrier evenly as I pound it out?


I saw a carrier bearing puller on youtube that attached to s slide hammer but cant seem to find one anywhere.

 

If you get it hot enough, the bearings will fall out.
That slide hammer for bearings would be a great thing to have.