half shaft boot band keeps breaking.

[Hellz]

so 2nd half shaft i have put in the drivers side.
1st one - rubber boot band broke close to the hub ( outer????)
half shaft was replaced when i had lower ball joint replaced (driver side). OEM is fine, just peace of mind.

2nd half sahft- replaced this past monday 1/3/11 when i replaced the lower ball (passenger side).. maybe 60 miles on it tops.
band on outer boot broken like the 1st. grease everywhere.. again..

not sure what could be the cause, but if i was to guess, i would say the band is hitting the zerk fitting on the lower ball joint? havent inspected yet but zerk is still there.(Moog ball joint)

these half shafts are from Napa auto parts.
http://www.napaonline.com/Search/Det...+50221+2221011

they list the same part # for both left and right....

anyways.. thougts and suggestions?

i wont be able to pull the old one this weekend, will have to wait till next weekend, on top of it i have to travel. so i will end up putting about 400 miles on it before it gets pulled.

i know it is easy as i replaced the driver side half shaft with vehicle on the ground and tire on. its tricky, and a pain, and hurts like a mofo when it is cold and you pinch fingers.. but doable. just dont have the time to get greasy.

the OEM half shafts are still good, and i still have them. passenger side half shaft was replaced on 1/3/11 when lower ball joint was replaced, i also swapped the bad half shaft on driver side with a good one. passenger side HS is doing good and still has band on it. if the band on this one breaks, ill be done with the napa line and will return both.