Polaris ACE Forum banner
1 - 20 of 33 Posts

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #1 ·
I have noticed something that disturbs me a bit, and I want to describe it, and see if anyone else is experiencing the same thing.

When I get my ACE up to a little above 40 MPH, I start to feel a vibration from the front end.
It feels like something is loose, or out of balance, or maybe coming apart.
The faster I go, the more pronounced the feeling is. But back down below 40 MPH, it's gone.

Then when I have it in AWD, and I am doing a steep hill climb and I feel the front wheels engage, I feel that same vibration.
But this time I'm doing maybe 15-20 MPH. It feels almost like it's binding up a little. When I turn off AWD or it disengages on its own, the vibration goes away.

I have more than 2600 miles on my RZR, and I do not feel this sensation in the RZR.
I have had the AWD bind up in the RZR a couple of times. But that was a different feeling - more of a binding, and less of a vibration rattle thing.
Then I just stopped, backed up about 20 feet, and it got better. It was not reproducible. This is reproducible and consistent.

Any ideas?
 

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #3 ·
Maybe your tires?
Wouldn't explain the 15 MPH hill climb shakes when in AWD. Does not happen on the same hill climbs with AWD off.
Of course, I could be describing two separate issues that happen to feel the same.

I've heard of people having balance issues with RipSaws that cause a shake/wobble, but I am running BigHorns - 25x8x12.
 

·
Registered
Joined
·
70 Posts
I was thinking same thing maybe two different issues.
I just had the same problem (vibration) at 25 mph with my dirt commanders. I took them off and put my stock tires on and vibration went away. I also put back on my rip saws and no vibration.
Do you have any extra tires you can try on it to see if vibration goes away?
 

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #5 ·
I do still have the stock wheels and tires.
I am planning to take them down from the attic tomorrow anyway, so I will throw them on there and go for a spin with the stockers, and see how that feels.
 

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #6 ·
Couldn't let it sit overnight, knew I'd lay awake in bed thinking about it.
Put the stockers back on, and I still feel it. If anything, it's worse.
 

·
Registered
Joined
·
44 Posts
It's defiantly the driveshaft going to front end causing vibration in the front gear case. Pull the driveshaft and it all will go away. Arctic cat has problems with this same thing.
 

·
Registered
Joined
·
358 Posts
It's defiantly the driveshaft going to front end causing vibration in the front gear case. Pull the driveshaft and it all will go away. Arctic cat has problems with this same thing.
Was it the universal joints in the shaft that they found a problem with in the Arctic cat?
 

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #9 ·
If it is the front drive shaft, why would it happen in 2WD? Is that shaft spinning at all times, and something inside the diff locks up for AWD, or does that shaft lay still until AWD is engaged?

I guess I can put the ACE up on stands and find that out for myself...
 

·
Registered
Joined
·
358 Posts
If it is the front drive shaft, why would it happen in 2WD? Is that shaft spinning at all times, and something inside the diff locks up for AWD, or does that shaft lay still until AWD is engaged?

I guess I can put the ACE up on stands and find that out for myself...
Good question, Scoundrel! I don't have mine to go look at yet. Hopefully by this afternoon.

My Ram pickup turns both driveshafts even if it is in 2WD. I can't say about the ACE. But putting it up on stands should give you an idea of what's causing it, as long as you're strapped in should it come off from the vibration. With the belt systems, it is hard to tell if it is U-joints going from reverse to drive like a car...

I'm curious if you could find it by running it on stands... Seems logical doesn't it?
 

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #11 ·
Well, I can definitely find out whether that shaft turns in 2WD while on stands, but I don't think I want to take it up to 50 MPH on stands. Eek!
 

·
Registered
Joined
·
358 Posts
You got that right!!!!!! We have to run FWD vehicles on dyno rollers. I hate doing that up to 75mph! Talk about squirrely!!!

At least you could tell if the front shaft is wobbling around if you set up a video to record it while you slowly speed it up to the point where you just feel it....
 

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #13 · (Edited)
I have the wheels off and the ACE up on a stand right now for other purposes, so I suspended a GoPro from the brake line,positioned a flashlight, and gave it a whirl (literally).
I did learn that the ACE's speedometer is probably in the transmission, and not based on how fast the front wheels are turning. That might account for some odometer-to-GPS discrepancies. :)
But other than that, I did not learn much, beyond the fact that the shaft does spin even in 2WD.

Here's the video.

 

·
Registered
Joined
·
358 Posts
Video came up private. As a check, since it is up off the floor, can you hold the drive shaft on the tranny side of the u-joint, and then move the front wheel back and forth to see if there is any play in the u-joint cross? Or does the shaft have any excessive play such that it could turn in an elliptical orbit?
 

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #15 ·
Forgot to hit the Publish button. It's live now.
I'll try and mess with that, but it's a tight squeeze in there.
 

·
Registered
Joined
·
358 Posts
Lookin at the video, I didn't see that the shaft was way out, but just a little wobbly on the start up which could be an optical illusion of the "video shutter" speed and the rotation of the shaft. Did you feel the vibration when it was running on the stands at the speed you were running?
 

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #17 ·
It wasn't a very good test platform. The camera was hanging by a velcro strap from the brake line, and the stand the vehicle was on is not very stable.
I was standing next to it depressing the gas pedal by hand. I didn't feel any vibrations, but that might be due to the wheels being off.

Anyway, the ACE is now at the dealer until Friday getting fluids and filters replaced and wheels/tires swapped out.
So maybe I'll look at this again next week when my actual jack stands are all available and I can feel safe enough to spin it up to 50 with the wheels still on, and do the wiggle test too.
 

·
Registered
Joined
·
358 Posts
that sounds like a great idea. thanks for the heads up and I hope that everything goes well. picked up my ace at the frame shop today and now it is home. next I will have to start putting the plastic bits back on, and get it cleaned up again. I will have to take the right rear wheel & tire and get the tire changed over to a new rim tomorrow.
 

·
Registered
Joined
·
44 Posts
The driveshaft is the issue. Not the u joints. The shaft is transferring bad harmonics from the rear drive axle case to the front. Mine starts about 45 mph and gets worse to 51. Arctic cat has a terrible problem with this issue on prowler 700 hdx models. The driveshaft to the front is hollow and transfers bad harmonics. Take it off and it's gone. Hope this helps.the bad harmonics are coming from rear transaxle and I doubt can be fixed without reengineer the wheel.
 

·
Registered
Joined
·
3,051 Posts
Discussion Starter · #20 ·
I hope that taking the shaft off is a suggested troubleshooting step, not a proposed solution.

I don't reach those speeds very often where I ride. If I rarely reach those speeds, will it be OK to just leave it alone, it will the thing fall apart eventually or something? Would that damage be accelerated by moving at those speeds for long periods, or often?
 
1 - 20 of 33 Posts
Top