CVT Problem? (again?)

[supertoast92]

My Helix seems to be producing a loud whining noise which depends on the speed I'm going (or the rpm of the engine, if in neutral). The faster I'm going (or higher the rpm if I rev it), it seems that the whine gets louder, and it I think it's coming from the CVT. Any ideas what it could be? Maybe the belt's caught on something? I'll take the cover off and inspect sometime today if I get the time.

[chuckorlando]

Couls be a bearing

[ckau]

I'll bet it's one if the gear shaft bearings in your internal transmission. I had the same whining noise in one of mine. It got louder until a bearing granades! the trans then locked up! I had no other damage except for the bearing it's self but the tranny wouldn't budge until I cleaned out and replaced the trashed bearing A rebuild kit with sets of bearing are avalible.
In the pic , it will be either # 5,6,7 or 8. Don't bother trying to figure which one, just replaced them all. If one is failing, the others are not far behind. No big deal, they will pop out. they are not pressed.
This is normaly due to poor lubrication, low oil level or poor quality lubricant. In my case, I drained the tranny and forgot to refill

[supertoast92]

But would the transmission not be moving when not in gear, just the CVT? The same whine occurs when I'm in neutral and sitting, just revving the engine.

[ckau]

Originally Posted by supertoast92

But would the transmission not be moving when not in gear, just the CVT? The same whine occurs when I'm in neutral and sitting, just revving the engine.

Yes it does , the internal trans is still spinning. Your neutral point is in the forward/reverse box, not the trans. The output shaft from the internal trans spins whenever the clutch engages.

[olderthan]

i don't think the helix actually has neutral just a area in between but your tranmission will
still be turning replace bearings

[supertoast92]

The gear selector is a 3-position, F, N and R, N being in between of course. But then again I wouldn't know enough to be able to tell you if it's true neutral or not.

[bige]

yes the helix does have a true neutral, pull the cvt cover and see if the fan is rubbing

[supertoast92]

Pulled it yesterday, the cover didn't seem to have any marks on it, nor did the variator fan or clutch bell. Funny thing is when I replaced the CVT the noise seemed to magically have stopped (or muted a bit). Maybe something is/was rubbing in there, but both nuts holding the clutch and variator were tight, so they weren't coming loose.

[SYCARMS]

Have you checked to see if you have fluid in the final drive? TOM

[supertoast92]

Final drive? How would I do that?

[SYCARMS]

On the back of engine you will have a drain plug on the underside and a fill plug on the left side of case. You will fill the unit just like a car rear end to the threads. If you go to American Sport Works web site you can download all the manuals, all you will need is your model number which I believe will be a 7150 but don't hold me to that. I would drain the factory fluids and replace with a high quality synthetic. TOM

[supertoast92]

Didn't get a chance yet to do so, but I want to note another possible symptom. It seems as if the go kart drags quite a bit when in motion. When I let off the gas, even on level terrain, it acts if I'm slightly braking. When in neutral, the kart moves freely. I can feel some drag, especially on pavement.

[SYCARMS]

Is your hand brake on, or adjusted to tight? Does the rear caliper hang , and do you have fluid in final drive. Best way to check is to put rear up on stands than inspect those 3 things. It might be a hung brake. Also check front brakes. TOM

[supertoast92]

Update: Today I finally made a trip to TS and bought some new 80/90 weight final gear oil, changed what was in the Helix. A lot came out when I drained it, so that wasn't the problem. At least I have fresh oil in there now.

I know for certain now that it's in the CVT, because there's a loud unusual sound coming from in the case when I put it in gear and slowly push it back and forth. Something's rubbing around the driven pulley, so I guess next thing to do is (once again) take that cover off. I took it off a few weeks ago, nothing looked like it was rubbing after a quick inspection.

Also for the brakes, they are definitely not hanging. Kart rolls easily on its own in neutral on flat ground. I'll probably run it on jack stands next time I take a look at the CVT.

[SYCARMS]

From what you describe it sounds as if it will be either in the gearbox or final drive. Did you notice any metal in the fluid drained? Tom

[supertoast92]

Nope, nothing was in the fluid. I think we have figured out that it's the bearing in the CVT case. I think it's starting to go. When the case is off and we push it back and forth in gear, the sound isn't there.