I had the spindles replaced on my New Holland 930b Finishing Mower and I am now breaking a tensioning spring every few hours even though I keep loosening the tension. I found this same problem identified on this forum about 15 years ago but I did not find any suggestions on how to solve the problem. I did find a possible cause being that pulleys on replacement spindles were larger than original which used up part of the belt length, hence, the belt was far to tight. As I said, I found no solution such as a longer belt or possibly a suggested measured distance between the tension system brackets to accommodate the larger pulleys. The local dealer has not been of any help. Thanks to anybody that can help. blmiller