Mysterious noise in the back, a tale of mystery and imagination.....

    Noise was present before the new wheels. Also other slingshot with stock wheels shows similar noise. This was my first point to polaris since they were quick to mention void warranty possibility thanks to custom wheels. My wheels have been rock solid, no issue with them or the tires.


    Noise intensity is much softer when vehicle is not under load which makes sense to me since the belt tension is reduced by a lot once the swing-arm is unloaded and extended. The video shows a softer noise because the belt is relatively dry. At the time I didn't realize moisture was a big factor. The noise is about the same whether weight on wheels or weight on swing-arm when assembly is wet. This is why I ruled out wheels and axle early on.


    I am tempted to see what the new belt does for the problem before I waste any more time and energy on this. Remember right now I have no noise and no issue as long as I keep her dry.


    My only concern is how the new belt will fit with the used pulleys. Service manual says 5k miles is the magic number before pulleys need to be changed with the belt and I am right there.


    Crusty dealership service guy says no biggie since the pulleys are still relatively new. A whole new can of worms if I have to deal with changing the pulleys, and expensive if polaris doesn't cover labor. No way am I doing that stuff myself. I saw the details in the manual, that's for professionals and their tools only.

    Quote from Funinthesun

    You could always take the old belt off and BEFORE installing the new belt, rotate the wheel to see if the noise is gone. That would confirm/eliminate the angle drive and belt as being the issue

    Good suggestion. I do plan to do that and thoroughly clean out the pulley's grooves to get rid of the grime build-up causing that obnoxious beading noise. My theory is that was a result of driving on sandy roads near the beach. The beading started happening shortly afterwards.

    this is what it sounds like when in dry conditions with the belt fully dry for days.


    It has to be a rubber issue, either the belt or some other rubber piece rubbing against something only heard when wet.

    The belt takes longer to make one revolution, that’s why I wanted the pulley marked.

    neostar

    Appreciate the feedback.

    I don't doubt a belt issue. Possibly a slight side separation that has created a v dimple in the belt. Laying the belt on each side on a flat surface might make it visible. Or it may not be present unless under stress.

    Could not tell from the jacked video if the rear was raised via the rear axle. I was leaning toward a damaged tire bead.


    Quote from Bigdog

    The belt takes longer to make one revolution, that’s why I wanted the pulley marked.

    Bigdog

    That info was stated by the OP in post #38. And most of us know that fact.

    Slingshot Flyer! Well, of course it's red... :REDSS:

    Quote from airoutlaw

    neostar

    ...

    Could not tell from the jacked video if the rear was raised via the rear axle. I was leaning toward a damaged tire bead.

    ...

    I had thought it might something tire related too but ruled it out when I heard the belt make noise with the tire suspended but like I said there are multiple noises I am dealing with here. That's an easy test since the noise is not currently present to just wet the tire and drive it around. If that rubber noise shows up then bingo it's the tire.


    One thing that has always bothered me about the tire is that even though the tire/wheel shop assured me that a 305 tire would have no problems with a 10 inch wheel I know the tire width is just outside the recommended range of the wheel so it's possible the tire could be the culprit for the main rubber noise. I will need to test that out. It just rained so I gotta wait for the roads to dry out before testing.


    FYI Cragar doesn't make 11 inch wheels in that style else I would have matched the 11 inch wheel of the SLR trim, I had to settle for 10 inch. The good news is that if I can confirm it's the tire causing the rubber noise then I can swap it out with my original tire to verify the fix and go from there. Glad you mentioned tire beading.

    You said the noise is loud when you make a turn....won’t turning put stress on the axle and bearings...



    This talks about driveline noise .... and top right it says proper cleaning of belt and pulleys can eliminate it.


    Listening to 2-3-4 different sounds all at once is baffling...

    I appreciate your input. When I read that section a while back I started listening to the rear when at speed, during acceleration, decel and when maintaining speed.

    One of the first sounds that stood out for me after just buying the vehicle was a cyclic swishing sound when at medium to high speed. That sound has always been there but is consistently "on" when maintaining speed but disappears during gas-on (accel) and gas-off(decel) moments. Next time you drive listen for it, it should be there and I expect it's normal.


    I strongly believe the service manual is referring to that sound. As an experiment a while back I purposely aligned the belt both far left, center and far right. I could tell the sound would start to be present at the appropriate points just like the manual stated for those different alignments. This sound is not the rubber sound that is vexing me by the way.


    Also the feedback I got from the experienced techs is to make sure the belt strongly aligned to the left. The manual clearly shows a graphic where there should be some teeth on the left showing for correct alignment.


    The interesting thing about that is when I have the alignment just right like the manual indicates the belt shows pretty much center on the front pulley but as I rotate the wheel what I saw was the belt was moving towards the center on the rear pulley then moving back to the left. This is what first clued me in to a warped belt.


    Here is what my belt shows currently after driving, I know for a fact it's further left than ideal because if it was perfectly lined-up it would be close to center on the front pulley but would cyclically travel to the center of the rear pulley when in motion, notice how this is not the case in these pics.


    So tonight I did some isolated tests, starting with a consistently quiet and dry back-end, I proceeded to do the following incrementally:

    1:carefully wet 360 degrees of the wheel rim (both sides), drive 3 miles, result:no noise generated

    2: carefully pour water on the inner-belt surface through a complete cycle, drive 3 miles, result: no noise generated

    3: carefully soak the rear pulley area only, drive 3 miles, result: no noise generated

    4: carefully drench the front pulley area only, drive 3 miles, result: no noise generated


    Clearly the wheel and tire are not a factor, individually none of the major components are producing the noise when wet.


    I still need to isolate the wheel axle as well.

    then I will go through a routine washing of the rear-area to include washing the belt per manual instruction, this should bring the noise back.


    BUT after 20 miles of driving afterwards and if for some batshit (get it) reason the noise does not return, then I am done. I will call the dealership and tell them to keep the belt ( I prefer not to take the risk with 5000 mile pulleys and a new belt) no telling what new noises that will incur. I will then for the next 2 years put up with the noise (if it eventually returns) put on at least 20k miles of more use then proceed to trade-in this wonderful but annoying toy for an electric vanderhall. Done!

    Quote from Bigdog

    You said the noise is loud when you make a turn....won’t turning put stress on the axle and bearings...

    It was one of the first things that came to mind when I first noticed how in one direction I got no noise but going in the other direction OR going straight the noise was there.


    Specifically the noise is there when going in a left-hand turn or driving straight then almost completely goes away in a right hand turns but there is still a hint of the noise.


    I made this very clear to polaris and the dealership in a video with the expectation that they would come back with blaming the axle or pulley bearings but they did not. And again right now, I have no noise in dry conditions making hard turns in either direction. Trust me, I have been doing this a lot trying to get the noise to come back via hard turns alone, but it's not happening.

    neostar ,

    I need to do a drive belt alignment. I have the necessary tools to do the alignment, but was wondering where is the best place to jack up the rear of the slingshot to make this adjustment?Also do you loosen the 30mm bolt completely or have some torque value on this bolt during the adjustment using the 22mm hex socket? Any information would be appreciated. Thanks in advance.

    Quote from SlingSC

    neostar ,

    I need to do a drive belt alignment. I have the necessary tools to do the alignment, but was wondering where is the best place to jack up the rear of the slingshot to make this adjustment?Also do you loosen the 30mm bolt completely or have some torque value on this bolt during the adjustment using the 22mm hex socket? Any information would be appreciated. Thanks in advance.

    I can't stress this point enough, you need to order the service manual from the polaris website. Don't rely on 2nd-hand information. It's important you have the manual in your hands before attempting this maintenance. Trust me, it's worth the purchase. The owner's manual will show you jack/hoist points for the vehicle.

    I have a version of the service manual on my iPad and iPhone ....


    The first thing I do when everyone is experiencing a problem is consult the manual for everything on that subject, including pictures.......not that I’m some kind of genius ...but I know how Einstein felt his entire life....he never had anyone on his level to talk to.....;):/

    Quote from neostar

    Good suggestion. I do plan to do that and thoroughly clean out the pulley's grooves to get rid of the grime build-up causing that obnoxious beading noise. My theory is that was a result of driving on sandy roads near the beach. The beading started happening shortly afterwards.

    Now that I read about the sand.....it could have ground off some of the contact surface of the belt and the pulleys....which could be causing some of the noise....maybe the noise is from the pulleys being “squeaky” clean...


    Could some of the sand worked it’s way into the bearing? And gouging up the axle surface....


    Before I know the real reason for what I’m about to say....I wondered why the mechanics were always “wasting” all that grease when I saw it squirting out of the bearing onto the ground. I mentioned that to a guy and he promptly informed me the reason for pumping all that grease until it was squinting on the ground was to “flush” out all the dirt that could be in there causing damage.......


    I’m thinking the bearings and axle should be carefully inspected for sand damage....it doesn’t take much to scratch up a polished surface.


    With all of the stress put on the two axle bearing just from normal operation......doing burnouts has to really stress them.




    Watching the slingshot commercials with them promoting doing donuts......it’s probably a scheme to void your warranty... after looking at your axle and bearings, drive belt and pulleys and angle drive......we can tell you’ve been doing warranty voiding donuts...sorry....

    Quote from SlingSC

    neostar ,

    I need to do a drive belt alignment. I have the necessary tools to do the alignment, but was wondering where is the best place to jack up the rear of the slingshot to make this adjustment?Also do you loosen the 30mm bolt completely or have some torque value on this bolt during the adjustment using the 22mm hex socket? Any information would be appreciated. Thanks in advance.

    You do? Never touched mine in 88,000 miles. In other words Polaris does not know how to adjust the belts

    Quote from FunCycle

    You do? Never touched mine in 88,000 miles. In other words Polaris does not know how to adjust the belts

    I think the belt drive design has a high tolerance for belt movement but the belt will begin to come off the left-biased position after a few thousand miles new. It happened to mine at around 2k miles and a buddy at 1300 miles. How detrimental is this to the drive system no idea but I suspect not much other than generating odd noises.

    Right now mine (belt) looks perfect at almost 19,000....I haven’t touched mine for any reason....I hear what I’m calling belt whine but nothing else unusual. I’m considering mine not broke so I’m not going to fix it.....


    We’ve all had some issues with this or that....maybe it comes down to the old...was it made on Monday or Friday...


    Not taking into account the defective parts installed at the factory that have been replaced under warranty.


    Nagging problems that can’t be found or not easily diagnosed are truly aggravating.

    Mystery finally solved:

    Even though my belt clearly is warped, it is not causing the major noise. The minor noise generated at a specific belt location showcased in my garage video is a nuisance but pales in comparison to the louder noise occurring in one wheel revolution. I suspect the belt drive system has a high tolerance for belt movement during rotations.


    The key to solving this issue was knowing that water/moisture would be the catalyst for causing the noise. One last area for a specific moisture test was the wheel axle.


    I initially poured water between the wheel hub and axle as well as the other side of the axle. After 6 miles of travel no sound heard but I kept thinking to myself the fact that the noise is heard more in a left hand turn and the opposite in the right hand turn tells me it has to be related to a leaning stress on the axle. This should have been obvious to the polaris rep that reviewed the video where I actually show the noise generated in a turn but it was not.


    So I decided to add more water and this time drive twenty miles in dry conditions and finally the noise started slowly coming back. The reason why it took so long was the water needed to seep into the axle bearings area in order to affect the lubrication of the bearings. This is also why it takes time for the noise to go away since the bearings area needs to completely dry out before the lubrication quiets down the bearings. Since I am not hearing popping noises, the bearings themselves are not being over-stressed they are simply being noisy.


    Is it a faulty bearing or is it a poor bearing design regarding moisture seepage? Before the bearing experts jump on the "I told you it's faulty bearings just like 4 years ago" remember this noise goes completely away and stays away as long as the axle remains dry I have over 250 miles of travel since I last had the noise. So to me the bearings are poorly sealed but the bearings themselves are fine because I can drive 45 mph hard 90 degree turns both left and right multiple times and not cause the bearings to make any noise as long as the axle remains dry. I even take the freeway clover-leaf turns at high speed and still not a peep from the axle bearings afterwards.


    I reported my findings to the polaris dealership tech and he agreed I need to take it in for close inspection. I am hoping in the end they will honor the warranty and change out the bearings but I wouldn't put it past them to blame my custom wheel even though I have video proof of other slingshots with stock wheels making the exact same noise.


    Word to the wise: occasionally turn off the radio and listen carefully to that back-end especially after getting wet in a rain storm a few miles earlier.