Big Bear Growling

[Myersob]

Hi all, this is my first post here and it's a question. We have 2 new 09 Big Bear 400 4X4 and we have noticed an odd sound when under a moderate load. Kind of a growning sound (not a joke) that appears to be coming from the rear drive. Since we rarely ever engage 4WD, we have only noticed it in 2WD at low speed usually climbing. Both of them do it, neither of them have reached first service mileage yet. Has anyone else experienced this with the BB 400 or any other for that matter? Is it something to be concerned about?
Thanks for any help...
OB

 

[Camo7]

Welcome aboard. Questions are good. That's why most of us join a forum to begin with. Any type of unusual noise is something to be concerned about. First thing to do is check the oil level in the rear diff. I don't know your mechanical ability so this could be really easy for you or something you're not familiar with at all. I'd be surprised if low oil levels were the problem in 2 new machines but that's the first thing I'd do. Next I'd talk to the dealer where you bought the bikes. I'm not sure of your warranty lengths in the States, but here in Canada we only get 6 months. That can go by pretty fast and then you're left with the problem yourself. If you let the dealer know and you want it checked out, then if it's something that is covered, you're not out of luck because of waiting too long. My 700 grizz is very quiet when moving and when I bought my 660, there was a lot of whining noise coming from the belt drive at mid to high speeds. It drove me nuts for the first while but now I don't notice it. This may be just a situation that the 400s have. Best to get it checked out while there's still warranty left though. Maybe even call or talk to a couple different dealers for different opinions. There's no such thing as too many questions.
Let us know what you find out.

 

[Myersob]

Thanks Camo. We have checked all fluid levels and we (my son & I) generally do our own maintenance. I have above average mechanical skills but little knowledge of ATV specific issues. We are going to change all fluids in both units this weekend. If the sound is still there both will be at the dealer Tuesday morning. Hopefully it's just a Big Bear thing. I know what you mean about the Grizzly whine. When we first got my wife's I took it right back to the dealer... they laughed. We're used to it now.

 

[grizztracks]

It's tough to try to diagnose without actually hearing it but as Camo said, I'd check all fluids and talk to a dealer. I think you'll probably find out or be told it's a normal noise. Hopefully you have a good dealer that's willing to do a thorough inspection. I've found taking them to a dealer usually is a waist of time because they very seldom have a place to do a test ride under the same conditions.

Because it only does it under a load makes me think it may be clutch or belt noise. If it were a differential I'd think it would make a howl or whine and be more noticeable at higher speeds rather than a grown under load. You may want to pull the clutch cover and inspect the belt and clutches. You could also drop the rear diff lube and engine oil to check for excessive metal shavings.

keep us posted.

 

[Myersob]

Initial Service on Fluids

Well, yesterday I was able to get the fluids and element changed on the Black BB400. Due to the weather here I have not been able to replicate the conditions that brought about the strange sound. I hope to be able to do that later today. Here is what I discovered during the maintenance process:
1) It took 3X as long to service the Big Bear 400 as it has any other ATV that I own.
2) It takes more tools, funnels etc... And patience!
3) Key service points are poorly designed (access/ location)
4) There was a lot of black goo on the final drive oil drain plug. The oil itself looked pretty good for a break in period drain. I assume (at least for now) that the black goo was from the Sealed Wet Brake. (???) comments welcome here!
5) Front Diff oil looked good.
6) The engine oil and filter element were both consistent with what I have seen on other initial services. (metal content)
As a side note, (as expected) the ATV runs and shifts much better. I am excited to test it to see if noise is gone. Will Post results.

 

[Myersob]

Just Maybe

We did get to test ride the BB Sunday evening on the same trails and under the same conditions as where the noises were heard. I am happy to report that we did not hear it. BUT, I am still somewhat skeptical to declare total success. Hopeful but skeptical. I'm going to give it a couple more rides just to be sure.

 

[Camo7]

keeping my fingers crossed for you

 

[Myersob]

Groaning is gone

I guess I can confidently say that the noise is gone. We have ridden over 80 miles since the service and have not heard it.
Thanks Camo and Grizz for your feedback.