I just picked up a 2004 600 twin sportsman today. When I try and change gears the shifter move easily and shows on screen it's in gear but doesn't move. I have to play with it a bit to get it into gear. When it does it makes a loud snapping noise and then moves. I noticed on the transmission that the shift shaft is loose I can wiggle it side to side. Anyone else have these issues?

 

See if the shift rod belcrank can be tightened or if it's stripped. If it's the shaft itself,then possibly could be problems in the external gear quadrant behind outer cover #3. 2004 Polaris A04CH59AF SPORTSMAN 600 (A04CH59AF/AH/AJ/AT/AV) Gearcase | Cycle Parts Warehouse 600 and 700 shared the same gear case and from the factory it was packed with grease. Water,can get in and make a mess of things. Here's some pics on a 700 that a Polaris Atv forum member posted.Hopefully this helps.Hard to Shift 700 Sportsman 2004 - Polaris ATV Forum

 

I also noticed that the rear left cv joint where it goes into the rear diff is pretty loose I can jiggle it.

 

Kind of a common thing as drive shafts wear especially on the plunging joint at the rear. As long as the boots are still ok,doesn't make the old click clacking noise,just see how it does for awhile after you sort out the shifting problem.

 

I've eliminated the noise to the transmission. I unhooked the rear prop shaft and front prop shaft. When I start it and put it in gear it makes a clanking in forward or reverse when I hit the gas. Any ideas what it could be and if it's fixable?

 

Does the noise seem like it's coming from the rear gear case or drive shaft area?

 

I think it's coming from the rear of the transmission

 

Could be the slider tracks in the plunging joint where the large ball bearings ride making the noise or could be one of the bearings that support the large drive gear in the gear case. I'd suspect the drive shaft if you kept up on rear gear case fluid changes. I know you mentioned play at the gear case but see if there is a lot of side to side play on the plunging joint by twisting the shaft.

 

I have the rear axles and rear diff removed. And unhooked the front prop shaft. And the noise sounds like it's coming from the transmission. I put it in gear and when I hit the gas it makes a snapping noise.

 

Ok then have you pulled the outer shift cover and checked the inner quadrant like I posted that this guy did.Hard to Shift 700 Sportsman 2004 - Polaris ATV Forum Could be jumping into gear when you give it throttle. Plus don't over look the clutches that can cause problems and make noise also. If you rule these out then sounds like a main gear case internal problem.