# Brute force rear differential problem!! Running hot extreme. Help!



## guimond47 (Oct 22, 2009)

i have a brute force 650i and after i got bk from my ride i decided to wash it. wen the water touched the rear diff, it steamed and was extreamly hot. i decided to check the fluid and it was BLACK and stinky. and it had a strong smell to it. I am gonna change the fluids in it. anyone know why this happend? 

i had brand new oil in it 5 rides ago......


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## NMKawierider (Apr 11, 2009)

Probably the brake is set too tight. Good luck with it man. Its probably damaged now.


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## wood butcher (May 11, 2009)

yea it sounds like the rear break is hangin


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## guimond47 (Oct 22, 2009)

ughh , and i just replace all the seals and bearings last yr. i guess gotta take her apart again........ or u think i should change my oil and see how it goes from there?


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## steeler (Feb 17, 2010)

loosen up the rear break then change the fluid, run it for a while (10-20 min) then change it again and see how it acts. thats what i would do. hope it works for ya
oh yea, what kinda fluid are you using? i use kawi wet break in the rear.


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## guimond47 (Oct 22, 2009)

only kawi wet brake fluids at all times. i just found this odd. is i possible taking the front of the rear diff apart while its on the bike? the brake section of it.


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## guimond47 (Oct 22, 2009)

took the diff apart today. one baring completly gone(input shaft bearing) and the brake pads are shredded . soo it explains it all. i thought kawi's wet braking system is saposse to last forever since its oil cooled


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## BIGPUN (Dec 20, 2008)

mine did the same. i been without brakes for a year. Does anybody know how to replace them


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## guimond47 (Oct 22, 2009)

*changing rear diff brakes*

Very easy , remove the rear differential from the bike, once that is done, remove the front part of the rear diff, which is where the brake system is located. once in there, u must know what ur doing unless u like to risk things. a service manual is very help full. calll the dealer , order new brake disc for the diff , u need 3 disc. replace em and put it back together. while u have your diff out, might as well change the bearings and seals while u there. its like 60 $ do do your bearings and seals. and about 30
$ per disc. it is time consuming task . it took me 2.5 hrs to remove the a arms and axels. im doing it a different way and leaving the diff in the frame and taking it apart in there.

let me know how it goes


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## drtj (May 3, 2009)

take pics & do a how to


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## guimond47 (Oct 22, 2009)

i would but the diff is already apart..... i can go from here and do a how to


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## drtj (May 3, 2009)

Put it back together & start over. Lol!! 

That will work. I wouldn't mind seeing the inside of one.


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## BleednGreen68 (Apr 19, 2010)

I would also check yer parking brake cable. Mud and water wreck havok on them. Mine was locked up solid. It would work when I set the parking brake but you had to manually pull the brake arm on the rear end to disengage it. Make sure its free and lube it often when doing your other maintenance. Sounds like you found the prob. Sucks you just rebuilt it. Well look on the bright side, bet you can take apart and put one together with yer eyes closed. Im a kawi mech and you got way more experience on the rears of brutes than i do haha. I've never seen the inside of the rears on the i brutes.


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## guimond47 (Oct 22, 2009)

thanks bleedngreen. ive took everything apart on my brute. only part i havent been in is the motor, i do not expect going in there either. i have a video of how the front locking differential works with the clutch basket locking it up. if u guys are interested on seeing it. let me know , i want to know how to upload vids on this site. i have many youtube vids that youse might be interested in. let me know


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## guimond47 (Oct 22, 2009)

and as for the rear brake cable, i removed it along time ago wen i bought the bike since it was seized.


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## BleednGreen68 (Apr 19, 2010)

Well those vids sound cool too see. You should atleast put the links to yer youtube page on the tech forums. I bet lots would like to see how it works. The rear would be nice to see since yer probably one of the few thats actually seen the inside of one. Its like a new world crackin open the rear ends haha.


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## BIGPUN (Dec 20, 2008)

where do u live, u can take mine apart


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## burmjohn (May 6, 2010)

Is Kawi break fluid the only stuff your supposed to run in the rear? Isnt there a mix of Kawi brake fluid and something else? I remember reading it in the manual (I could be wrong) - but I'd like to know as I just bought a bottle and I am about to do my first rear oil change. 
Thanks 
- John


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## Medic_Up (Feb 5, 2010)

burmjohn said:


> Is Kawi break fluid the only stuff your supposed to run in the rear? Isnt there a mix of Kawi brake fluid and something else? I remember reading it in the manual (I could be wrong) - but I'd like to know as I just bought a bottle and I am about to do my first rear oil change.
> Thanks
> - John


 
You can run tractor hydrolic (?) fluid but it has to be for wet brake applications...One gallon is like $9 and it only takes .7 qt...


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## burmjohn (May 6, 2010)

Yeah but is kawi wet brake (what I bought) the only thing to put in there with out any other additives? 

The manual says "Kawa Chem Gear & Wet Brake Oil" as in they are supposed to be mixed.


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## Medic_Up (Feb 5, 2010)

Sounds like they are pre-mixed.. I havent bought any like that I just bought the hydro fluid, I havent had any trouble from it..

I realy cant answer your question.. sorry


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## burmjohn (May 6, 2010)

After googling around, it seems its the same crap. So no worries, just a newbie brute owner trying to make sure I do things right


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## guimond47 (Oct 22, 2009)

i live in sudbury ontario . a little far away from u i must immagine. lmao , guys i totally forget to take the pics while re assembling the diff. SRRY!. but like i said i have a vid on how the front diff works if anyone is interested on seeing it. thanks


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## BIGPUN (Dec 20, 2008)

so can somebody do a how to on replacing rear brakes


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## MeanGreenMan (May 24, 2010)

*3 things to clarify:*

*1. All Prairie & BF Rear Gear Box* 
It's NOT a differentiating type. There is no spider gear to differentiate the left/right wheel speeds. It's just a plain 1:1 ratio gear box and both left/right rear wheels turn at the exactly same rate. That's why you hear that rear tire squeling noise when riding on hard pavement. Only the front wheels are differentiating (since it has the front "diff" gear box).

*2. Wet Brake Oil for Rear Gear Box*
Following are suitable in addition to Kawi WET BRAKE oil
> Mobil 424
> Exxon Hydraulic 560
> Citgo Transgard Tractor Hydraulic Fluid. 
Kawi oil is exactly same as the Citgo oil, just re-bottled. And it's not mixed with anything else.

*3. Why the Input Shaft Bearing Failed inside the Rear Gear Box?*
> Check the retaininng nut that holds the bearing in place. If that big NUT has come loose , the bearing would walk out and get chewed up inside the gear box. Make sure you apply loctite when you install a new nut to prevent loosening again. Yea, a loose NUT can cause a big problem on quads. 

*MGM*


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## 15brute (Jan 24, 2010)

Its not a mix of those 2 things, Kawa Chem gear and wet brake oil is just one fluid.


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## 15brute (Jan 24, 2010)

^^^^^^My bad, somebody beat me to the punch!!!!


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## BleednGreen68 (Apr 19, 2010)

No thats what kawi calls their rear end oil. Kawa chem is what they call their oils and stuff. Just a name they gave it. You HAVE to use that oil or the hydraulic oil. I always use the kawi oil since its always on our shelves. Its only like 6 bucks i think. Most of the bigger tractors have internal wet brakes also so their hydraulic oil has the same additives.


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## vtfast (Feb 19, 2009)

This also happened to my 650i, Kawasuki knows about the problem and we the people need to start a class action against them for such a pitiful design. the forward pinion bearing retainer is coming out of the factory without locktite on the retainer and it's a bad design to begin with. Mine got so hot it blew fluid out the vent tube and burned me severely on my legs, Kawasuki told me to take a hike. 

Any lawyers willing to take a stance on this one?


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