I need help! (not the kind my wife says I need) The 4x4 on my 04.5 Sportsman 600 twin randomly engages and I can't figure why (typically around 15 mph). I've read all the threads I can find on this site and can't diagnose where the problem lies. Here's a list of what I've done:

1. AWD switch - removed, cleaned all contacts, looked just fine
2. Drained the front Differential fluid and replaced with the correct amount of Polaris drive demand fluid
3. Drained and refilled a 2nd time with the appropriate level of drive demand fluid
4. Removed the front differential and disassembled - roller cage, armature plate and everything else in there looks like brand new. Absolutely no filings, no cracks, nothing...

I'm stumped and after all this work I don't know what else to do. With a new baby on the way, I'm trying to save some money and NOTbring it to the dealer.

Am I missing something incredibly simple? Thanks for your help.

 

Did you check to see if the armature plate was magnetized to the coil? Was it easy to place and remove without any resistance? Any deep wear marks on the the back of the plate? This and the the roller cage I would have replaced while I was in there just to be sure. OPT

 

Thanks OPT, I still have the diff out and pulled out the armature plate. There is slight surface rubbing on the armature plate, but not even noticable when running my finger over it. The plate itself removes very easily. If there's any magnetization, it is slim to none.

When I put the diff back together and ran 12 volts directly to the plug it engages perfectly. When I reverse the connection it disengages as it should. Would I need to reverse the connection to make it disengage or should it simply disengage when I remove the power suppy.

 

When you disengage power the armature plate should be free with no resistance or sticking. Not worth taking the chance of having to pull it back out again.If you still have it apart replace the plate along with the cage (best to get the updated aluminum cage). Plus any thing that looks worn.There has to be something causing the erratic operation unless you can trace it to an electrical problem. OPT

 

Thank you sir for you insight. I had an electrical guy over to diagnose the electronics and with the wiring diagrams and his tools, we determined it is not electrical. I will be placing the order for the JD parts everyone has discussed. I can't bring myself to spend the $140 on the aluminum and haven't heard anything negative about the John Deere. Despite not being able to see any damage to anything in the front differential, I will order the armature plate and cage kit.

I will hope for the best...

 

I have a 05 800 sp. When did the cage go aluminum? duh! always worked in the fool proof hub.