I have an 03 Sportsman 500 HO. This problem has occured once before and required a "service tech" to fix. The price was waaaayyy too high and the explanation of the problem was way too fuzzy to trust. Here go's...My left front wheel will not engage when in four wheel drive. I know the system fairly well as I've had it apart numerous times, too many to count. With the wheel off and the armature plate exposed, I engage the four wheel drive to discover the magnetic pull that should be there. It draws the plate to the coil. I carefully reassemble taking care to line the plate up as it should be with the three "fingers" in the slots, all bearings in place, etc. I fill the hub up completely with the proper fluid and wham..no engagement. The clutch assembly looks fine, everything is as it should be. When serviced with this same problem the dealer essentially replaced the entire strut, never really stating what the problem was. I don't think they knew. The frustrating part is that I have the magnetic pull when disassembled. Anyone have this mystery on theyre quad? Suggestions please as I'm out of ideas, would hate to invest in the whole system as it's expensive. This all came about by the way when I lost my ball joint on the same side, the front tire folded out at a very low speed (fortunately) All wires are still in place and in fact there was very little damage incurred. At least visible damage....

 

Make sure the axle stub shaft (the part that goes through the hub) in not bent. Jack the bike up off the ground in 2wd and see if the wheel has any side to side runout with the axle turning and the wheel stationary.

Then you might have to pull it apart to check the clearance between the plate and the coil. Don't quote me but I think it's 0.006". If there is too muck gap or too little it will not engage or engage in 2wd.

Just some suggestions, as my old Scrammy would do the same thing sometimes.

Todd

 

Oh and check the resistance across the coil. I don't know what it should be but compare it to the other side. And wiggle the wires at the same time to see if there is an open in the circuit intermitantly

 

Did you ever figure this out? I spent a few hours disassembling and reassembling the left hub. It is doing EXACTLY what you described. I did the same test with the armature plate while it was disassembled and it's got good magnetic pull. The resistance across the coil is 25 ohms. I even switched the hubs left and right to see if the problem followed the hub. It did not.

????????????

 

check the armature plate for wear and see if the three tabs on it are in good shape and not bent.clean thelock in hub and bearings good and check the washer that goes inside of it for smooth rotation and sliding in and out.it might be worn and causing it to bind.and be sure to check the wires leading from the hub to the electric board are not broke or scraped up.

 

I am in midstream right now. I've pulled the entire left side shock housing off the unit and have it on my bench. What I was trying to do is figure out how the outer ring is adjustable as the manual states. I'm supposed to be able to tap the seal in between the two rings (inner and outer) and this should move the outer ring. No luck so far. What I have done though is tear the wiring which forms the coil assuring that I now need a new coil. What I don't know is how the coil is removed and a new one installed. It's a mystery in that the manual that I have is not too detailed, really giving no detail. Anyone ever dne this? I'm trying to save some money by nt buying the entire shock housing, just the necessary pieces.

 

the coil is knocked out.and cost about $100 i would buy a used strut off of ebay if i were you.

 

I adjusted that outer ring and it works now. The outer ring was a little too far out. I tapped it in a little with a mallet and a big flat piece of aluminum bar stock. I took it for a test ride and it worked just fine. But then guess what happened .......... the left REAR hub striped out and now I back to 3 wheel drive. Man...........

 

Thanks for the info and good work on the front hub. Too bad about the rear.

 

i have a rear 4 on 4 hub off of a 400 explorer.