A friend of mine snapped his rear axle on his AC 400 FIS 4X4 about 2 rides after he just had a non pro mechanic replace it. Is there a special way the CV's must be aligned when the new axle is installed to prevent binding? Does anyone know where instructions for replacing an axle are? The ATV has been wrecked a few times, the A arms look straight, but I am trying to figure out what could be causing the axles to break.

 

ive done my 2002 500 a couple times to change the seals. Pull the brake calibers off,shocks ,(just the bottom part connected to the a-arm), wheel hub, use a rubber mallet to knock the a arm off of the hub, you need to get everything off so you will have just the half shaft(axle) by itself. once everything is removed that needs to be removed, grab the half shaft with both hands and pop it off. This may sound easier than it is. I have heard several people say it would not come off. There is a C clip inside the differential holding the axle in place. So basicaly you have to jerk on it really hard to pop it off. Like i said it may be hard to do. I was lucky, both of mine came off in 1 pull. when i put mine on, there is was no special way,the splines will line up automaticly, just slide it in till it snaps past the C clip. when your done,make sure the fluid is replaced.

 

Mudslingingfool is right on the money. Only thing I would add is once you are ready to pull the axle out push it in first. This pucshes the CV jount into its knuckle so that when you pull straigh out it acts like a slide hammer. Also, make sure that c-clip is onthe end of the axle. I have had it come off before while removing an axle. Spent a lot of time looking for it on my shop floor then went and bought one. I found the original one when I went to grease the splines where the axle slide in. Now I always check. Even the instructions say "account for the C-clip".

Now why it is breaking? If I am understanding you correctly it was just replaced? If so was it the correct one? Are you running large tires? What were you doing when it broke? If you were spinning the tires in mud and then the tires catch that can apply some stress to the axle. Are the wheel bearings good so there is no slop in the axle. My friend broke his rear axle by getting a large rock wedged between the rim and the brake caliper on the front. He broke the brake caliper off and he fixed that and the next ride was spinning the tires in some mud and BAM! the axle breaks right at the splines where the CV joint attaches. We think it was damaged when the break went. He then had further bad luck becasue as soon as that was fixed on his next ride his front diff locked up! It appears that it was damaged either when the brake caliper broke or the axle broke and was not seen. So you might want to inspect the differential real good as well.

Hope this helps

SJ