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Discussion Starter · #1 ·
A test drive on rather steep inclines revealed an undesirable condition. When the vehicle is in 4x4 mode and slows to near zero speed ~~0.5 MPH or less it shifts automatically out of 4x4 (as indicated by the dash LCD display and operation).

The problem occurs when you are descending a steep hill in 4x4. As you try to slow and creep the Brutus will shift to 4x2 and the rear wheels will lock. It will stay in 4x2 even if you add throttle via the orange handle. Only if you speed up by adding forward pedal to go faster will the 4x4 re-engage. It appears to be totally dictated by vehicle speed. If there is any side camber on the hill the rear will slide in that direction.

I expect this to be a liability issue for Polaris. Driver control is greatly reduced when the rear and front wheels are not connected via 4x4 mode. Under the right conditions the vehicle could slide sideways and could roll.

QUESTION:
Can this reversion to 4x2 be disabled somehow? Computer code change? Removing a speed sensor? Otherwise there is no way the vehicle will be suitable for our use traversing a 25 degree grade gravel hill, etc.

I expect only a factory engineering representative can answer this question.
 

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I posted a couple of comments here on this thread.

http://www.brutusforum.com/forum/po...rutus-up-down-hills-experiences-needed-2.html

I understand your question a little better with your new thread. I don't think this can be changed, and I could be completely wrong. But I own a Brutus. When going forward down a hill, even though you have "some" gas on the pedal, it's a hydrostatic, they do respond differently.

Lets say your traveling down a hill at 30%, and you have the pedal pushed in to 15%, in order for the 4x4 system to engage, you need to be above the 30% (pedal wise) of your forward movement. Very hard to describe and I'm not an engineer. Just things I have noticed with the Brutus.

For example. My Brutus at times will max out at 40mph. If I have the rear diff locked and am going down at hill at 45mph, but have the pedal floored, the rear diff will disengage. It's almost like if the Brutus is going faster than what you have the pedal pushed down for those RPM's at said speed, you loose the traction setting you have engaged.

This might be the norm for a hydrostatic machines. I had similar experiences with a John Deere lawn tractor that was hydrostatic.

This thing is not "king of the hill". When I say king of the hill, I mean it hates hills. But that's not what this thing was designed for. It's not a 900XP. The other day I dropped an entire half of a tree. Very heavy, bottom diameter of the tree was about 2.5 feet and the tree was about 45ft tall. Pulled it no problem to where I needed it (about 800 yards away) for me to cut it up and get rid of the trash branches.

If you are a large property owner, this thing is king kong. You have attachments for this thing that can get any job done, and it does it well. This IS NOT A TRAIL machine.
 

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All in all, I love my Brutus. I have the blower attachment right now, plan on getting the sweeper and the bucket for sure!
 

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]I look back at the factory description and it doesn't say all time four wheel drive it describes it as four wheel drive when needed so going down the hill I'm sure the system senses that it doesn't need 4 wheel drive to maintain Tracton.I could see this being undesirable when you want the front wheels to pull you around the corner on a steep ridge I agree with you i think it would be a good idea to have a switch to lock in four wheel drive
 

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Just posted this on the other thread:

The Polaris system is more of an all wheel drive system. When the rear drive wheels start to spin, the front two wheels are engaged. In the OP's situation, since the wheels aren't spinning when trying to propel the vehicle forward, perhaps the AWD system is not engaged?
 

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Discussion Starter · #7 ·
All good input. Really hoping someone has specific technical knowledge about this particular condition.

Is there a service manual available?

Is the drive train configured as:
1) engine connected to
2) hydrostat connected to
3) manual trans (Hi, low, neutral)
4) rear axle and front axle via disconnect mechanisms.

or:
1) engine connected to
2) manual trans (Hi, low, neutral)
3) hydrostat connected to rear axle and front axle via disconnect mechanisms.
 

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Water Temp on my new Brutus 2013.

My water temp is 210 to 215F with outside temp at 95 degrees F while mowing.
Does this sound a little high.
I have checked the radiator fins to be sure they are clean.
Tom Johnson
 

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"Chapter_05_Engine_Cooling_System.pdf"

Tom, you need "Chapter_05_Engine_Cooling_System.pdf".

The fan should kick in at 194F. The warning light is set to come on at 230F.
 
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