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Is My Diff Bad?

6687 Views 13 Replies 4 Participants Last post by  bushwacker
I’ve got a 13’ Brutus. Absolutely love it and have had it for a little over a year. I’ve noticed over the last several months it won’t come out of 4wd into 2wd unless I go in reverse. It also seems to accelerate slower (notblije they aren’t already slow enough). There is also a slight squeak in the front axles somewhere. It also seems to struggle going up inclines unless I turn the rpms up all the way. I did some googling and it looks like front diffs on the 13’ aren’t all that reliable. Thanks for any input.
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I feel your pain... When the gear lash is tight the soleniod does not have the power to disengage. This occurs on slopes from the vehicle weight and from tires spinning at different rates of speed due to wear. If you look closely a rear tire is worn more than the other, likewise on the front. You turn radius in 4 wheeldrive is now also limited by binding. The fix will be frequent tire rotation left to right and front to back. That looks better with the same width wheels, lol, or it's time for new tires. A better front diff also helps, the RZR racing diffs are a direct fit and much better, but the tire problem is the main culprit, closely followed by the slope issue.
Ghost Rider: What about the opposite of TNT70's issue. My 2013 just decided not to engage the front differential today. Could it be a solenoid or relay issue? I had thought it seemed to have a slight difficulty disengaging the front differential over this last winter.
Check the plug at the front diff when 4 wheel is selected, current present, it's the solenoid or sprague is going inside the diff preventing the solenoid from engaging. The Sprague is a composite matrix material (plastic). Done away with in 2015 for an aluminum casting. Of course you might get lucky and find the front diff was just unplugged...
Check out this picture, note the armature drive tabs activated by the coil are your solenoid. On your machine this is plastic with only 8 pins, the picture has the Polaris replacement with the aluminum cage or sprague with 10 pins. What happens is the plastic shears leaving nothing for armature tangs to drive. The Tang thickness is about 1/16 of an inch. With the key on 4 wheel selected you should see 11-12vdc at the plug.


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The coil inside the diff should read between 21.6 - 26.4 Ohms of resistance. What ever you do drive the pin out of the drive shaft at the diff first should you decide to remove the diff.
Voltage and resistance are good. Next step, remove the and repair the differential. I hope to be able to put it back together without the diff so I can use it while i get the parts.
Have not considered that before, perhaps pull the axles. But you will need to pull both wheels and hubs to get the axles out. Might consider removing the cover and internals of the diff, only one side to pull wheel and hub. Then you can get the cover back on and axle back in. Anybody else have some thoughts?
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Ahh checking and you loose the axle connection pulling the diff internals. Guess pulling both axles is your best bet.
A wood block and a hammer blow on the end of the axle then yank it right out is how they release from the diff. Just in case you were not sure.
After hours of pulling everything apart and and investigating... Nothing was broken in the differential. I also have the aluminum sprague carrier to my suprise. I thought I had a bad all wheel drive switch, or a relay issue.

The problem ended up being my neutral switch problem that I had earlier this month. I jumpered the switch so that I could start the Brutus in low or high gear, but doing so, it disabled the computer from sending the correct voltage to front differential. I had called my local bobcat rep looking for info regarding a relay for the 4 wheel drive, turns out it is wired through the computer which must monitor the neutral switch.

Four wheel drive works again now that I disconnected the jumpered neutral switch. New switch on order. I attached pictures of my fully functional front differential...
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2013 Brutus HD PTO - Inside of Front Differential

Here are the pictures of my front differential.


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Glad to see the diff is in good working order, great info on the neutral safety switch being the culprit! I did not know that, thanks for following up with the solution.
I am having the same issue, and wouldn't you know, I just happened to have recently jumped the neutral safety switch. facepalm!
but this would lead me to another issue. I have been having issues starting the machine and that is why I jumped the switch. from what I could tell, the switch itself was not the issue. it looked to me like the command lever pivot mount was wobbled out and would not allow the neutral switch to properly function/seat in neutral. I guess I need to go back in and figure another way to solve the NSS issue. though it is strange, the AWD does not require the machine to be in neutral to engage, or vise versa. I guess I would just wire another switch in line that would bypass the jumped switch when the awd is needed. just a thought. maybe just fix the neutral switch issue. but that thing has always been a pain in the but it seems for starting.
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