I have a prairie 650 (02) last week I noticed that when I switch from 4 to 2 wheel drive it dosent switch as fast as it did.It also grinds or bangs in real hard, any ideas on what might be the problem. Thanx kevin

 

I would start with changing the diff fluid, then moving to more advanced problems. On the otherhand, chenging the fluid may not help because the damge is done. It might also just need to be adjusted

 

Here is how to tuen up your front diff gear case.
Change front diff oil and look for any shiny metal debris which is not a good sign... Use synthetic 10W-40 oil by the way. The drain bolt (allen head) can be EASILY stripped and super tight from the factory. Clean really well the bolt head where the allen wrench would fit. Get a long breaker bar and give a good torque to loosen it free. Next is to pull out the 2/4WD shift actuator from the gear case and inspect the small 1/2"x3/4" metal block at the end of the actuator motor shaft for any wear. Believe it or not, this small metal piece is doing all the shifting (actual contact point) work. If it has rounded corners, replace it (apply moly grease when installing). Also, it is a good idea to disassemble the actuator housing and clean/grease up all internal gears.

 

Hayashi, thanks for the info.Do you think this might have somthing to do with shifting from 2 to 4 wheeldrive while machine is still moving, or just normal wear and tear.The machine only has 850 miles on it. Thanx again

 

How to shift 2WD->4WD->2WD:
The best way is to do it either when completely stopped or moving very slowly 1~2 mph on SOFT packed dirt or sand. It is easier for the gears to mesh together, in other words requires less force to synchronize. I think the Kawi system is programmed not to shift above 12 mph for that reason (you can toggle the switch at any speeds but it ).

Wear and Tear:
The biggest wear and tear on that system is the small steel block that I described earlier. Next biggie is the spider gears (2) and the stationary shaft. Look for any sign of seizure or over heating (due to too much friction) on the shaft surface. This requires a complete disassembly of the gear box. For me, getting in and out the gear box on the ATV is more work than actually disassemblying the gear box. Another wear item is the 2/4WD actuator. There is no real mechanical wear on internal gears (as long as you don't let water/mud in), but the potentiometer inside the actuator which detects the angular position of the dc motor shaft wears out and develops too much friction sending out dirty signal (irregular return voltage) to the control unit.

Good Luck.