what would cause the axle/boot to break?

 

Normal use.

Also the boot does tear after a while and dirt, debris, and sand will get in there. Once that happens it is only a matter of time before the CV fails. To prolong the life of your boot you can avoid cranking your wheel all the way to the end whenever possible.

"dropping" or "slammin" your car can also have adverse effects on your axles.

 

maybe i should raise my car up a bit?

2 axles in one day.. pretty nifty eh?

the axles broke at the same spot both times, the boot between the intermediate shaft and axle. dropped 1st gear and shifted. boom, click click

 

Are you sure you are using the right axle for the car?

 

yup.

non abs 94 integra axles

 

spinning in mud or gravel or being too old cracking and getting dust and whatever from the road then buh bye cv joint

 

how much power are you running? If its even just a decent amount it might be a good idea lookin into getting a pair of beefier axles maybe hasport or something cheaper?