I have a 07 Sportsman 500 EFI and the 4wheel drive is disengaging. While in low range and high range not under work load it will disengage. Then once you get on it again it won't be in 4wheel drive and I will have to stop and it will engage again. The icon disappears while disengaged and will comeback when engaged. It has never done this before and I would like to know if there is an easy fix or if I should take it in.

 

that does sound strange for sure. it suppose to sense when theres 1/5 of a wheel spin to engage the awd drive and kick out when not needed going back to 2x4. seems almost liek what ever is used to sse the wheel spin is messed up? hopefully someone can shread some light on this.

 

AWD will disengage randomly, but when I come to a stop it will engage. Any answers to why this is happening? Oh when it disengages the little light in the Speedo goes off that is how I have been noticing this other then the fact that I almost buried it ice fishing until I let of the throttle and it engaged again. Very weird my dad is changing the front diff fluid and he has unhooked the battery to see if it would resent itself to no success. Any help would be a huge help need to get this figured out. Thanks

 

Starting to wonder if changing to a size bigger tires has cause this problem? It worked fine before the new meats, so it makes me wonder if the tires are causing the issue. Again any info is greatly appreciated.

 

The way the on-demand system works is that there is a gear ratio difference between front and rear axles. The front ring gear is turning slower than the rear ring gear by about 20%. Once you activate AWD with the switch, you are energizing an electromagnetic coil in the front gearbox and are still in 2wd until the rear wheels slip. When you have traction, the rear wheels are driving (100 rpm for example). This makes the vehicle move and the front wheels will roll at the same speed (100 rpm). If you lose traction at the rear, those tires may still be turning (100 rpm), but because they are slipping, the front tires start to roll slower and slower (100, 95, 90 rpm, etc). Once they have slowed enough that the front ring gear is going faster than the front tires (80rpm vs 79.999), relative motion between the roller cage and ring gear cause the roller clutch to cam out and lock the ring gear to the front axles. Now you are actually in 4x4 and the front and rear are turning at different speeds. Once you regain traction at the rear tires, they propel the vehicle again and the front tires roll at the same speed as the rear and the roller clutch unlocks. This AWD On-demand operating principle dictates there be a speed ratio front to rear. The ratio difference is somewhat defined by wheelbase and trackwidth so that the front doesn't try to lock in during tight turns.
Changing tires shouldn't affect things, unless you have different size front to rear. A one inch tire diameter difference would change that "gear ratio difference" a slight amount...probably not noticeable. 2" or more probably would be, but it wouldn't make it not function...it would just change the amount of slip needed to get it to engage. Once engaged, if you maintain torque, the unit usually stays locked in and wouldn't pop out like you described while getting stuck ice fishing.
If the front gearbox is not getting electrical power due to a bad wire, the coil would not be energized when AWD is selected and the front would not engage. An intermittent connection would make it come and go. It could be a broken cage inside the front gearbox...rollers aren't being held in the proper location and aren't able to wedge properly. I had trouble once with my machine not giving me AWD in reverse, even with the rev limiter button held. After disconnecting my battery for several minutes while installing a winch, that issue seemed to go away...must have been something with the control box?

Good luck!

 

posting reply for my son...


well the problem seems fixed,drove around in circles and the gear selection light stayed on perfectly and the AWD light never went out on a short ride...not sure why,did too many things at once to pin point the cure...

after the rain stopped I soldered high beam wires and the high beam works again...
cut off 5" of that ribbed plastic conduit that was the cause of the high beam wires breaking,well that and a hard hit on the culvert,high beam never worked after that hit...
used dielectric grease on all the electrical connections when putting it back together...

perhaps(iffy at best) the broken wires were touching on the hard turns and causing the gear selection light to go off and the AWD light to go off and on(no pattern to the AWD light going on and off)...