I have owned this 250 AC auto since new. Just at 200 Klics, little less than 200 miles. Seems if you try to engage the transmission with a high idle it breaks them. No forward and a jerky reverse. I took it to my nearest dealer, they figured it would take 8 or 9 hours plus parts. @ $80 an hour! Well I am just not going to pay it. Can't pay, I no longer have my good paying job. So I well be doing the work my self using what appears to be the AC service manual. I hope to document the repair and add it here for future owners.
If I knew then what I know now, I would have bought a polaris 350 4x4. This ATV is fine on flat smooth ground, problem is every where we ride it is rare to find flat smooth terrain in the Texas Hill Country, lots of limestone, ledges, rocks. Heck it is great for pulling my little trailer around the yard, running to the restroom at camp. Just keep it away from off camber rocky areas. It wants to roll over, the solid rear axle is the problem.

 

What year is you Cat? I'm assuming it is a relatively new one as you said it had a solid rear axle.

 

I have a 2008, it has a place to mount a ball hitch and since I have a large yard I thought it would be great. I have a couple of trailers I use for yard work and projects. I would have liked to use it on the current project but alas, it shall not happen.

 

Symptoms that the auto tranny is beginning to fail.
Starts with the unit not going into gear normal H(HI) mode. Requires shifting to L (low).
Makes something akin to a grinding noise when engaged.
You have to press the shifter lever at the input shaft as there doesn't seem to be enough "throw" to get it engaged.

If you are having this problem expect catastrophic failure soon.

 

This is the culprit.
The "drive shaft"#3303-791 $73.70
and the "counter gear" # 3303-793 $36.85
needs the bearing#3304-067 $13.00



Drop the rear end after you remove the calipers.
to separate the cassette from the transmission housing use a large screwdriver or flat bar and wedge only at the bolt holes mounting points. You do not want to damage the mating surfaces. Wack the cassette with a rubber mallet as you pry.
Removing the "drive shaft" undo the retainer inside the tranny case. You also need to remove the drive gear and drive wheel on the left side of the engine.

To get the gear cluster out of the cassette. Remove the speedo drive gear and tap the bevel gear with the mallet.

Took my son and I about 2 hours to get it apart. Now the trick well be removing the counter gear from the shaft and installing a new one. Pressing the bearing on the drive shaft well require a press and a bearing tool. Harbor Freight has what i need.

 

1. When you take out the cassette, make a note of how many washers are on the ends of the shafts and their thickness. These are called shims in the parts drawing.

2. Getting the gear clusters to fall out and apart is easy, your going to have to put them all back in about the same time, Meaning you need to put both gear clusters, shift forks, shift drum in at nearly the same time. This well take practice. It took me about 10 trys to figure out how to easily get it together.

3. I took my parts to a shop, it took a 20 ton press to get the parts on. This is no heat and cold gear pulling event, ain't gonna happen,. Took 18 tons to press the counter gear on. .

4. You can not "save" the bearing on the drive shaft. just go ahead and buy a new one. It has to be pressed off and that is going to destroy it.

5. There are two (2) bolts on top of the transmission, one is an oil fill the other is for the shift drum detent spring and ball. The outer is the oil fill.

6. The shift shaft and shift drum have alignment dots. I don't know how the factory does it and the manual shows every thing from the inner case but the real world the outer case and gears are bolted together by a circlip and two allen bolts that can not be accessed from any where but the outer case on a bench. The dots can not be seen so you just mark the teeth with a sharpie.



I tried making a video of how to put the cassette back together but i just don't have the video equipment and time. Any questions feel free to post up or send me a e-mail. BTW I have it installed and am re-assembling the ATV. I need to pull the front bumper and have it straightened and the handle bars are bent.

 

I have to do the same thing except i have more stuff chewed up and my counter shaft is broken in half. Does anyone know what kind of oil goes in the trans? And what the torque specs are on that front cover?

 

I just did an oil change on my '09 250 & it holds 500ml of AMSOIL 75w90 Servere Gear Synthetic.

Can't help on the torque specs.

 

Got any images? I am betting this is a common problem with the "autos". How many miles on your 250?
Mine is less than 200 miles

 

I dont hav any pics on my right now but i will take some for you. It has 450 miles on it but its an 07