I have a Traben Array Ltd 5 string bass that I bought new 9 years ago. I just had the FOURTH Grover machine head fail. The shaft separates from the gear. It appears that the shaft is just pressed onto the gear and it is held there by a tiny screw. Grover has been good about sending out replacements each time but I can't tolerate the two week down time. They tell me they never see this problem with anyone but me. I am wondering two things: is anyone else experiencing this problem and does anyone have any idea why this would keep happening or a solution to the problem? I've even added a string hold down between the nut and the tuners (it only holds down the A and D strings) thinking that perhaps the wraps were too high, even though I am careful not to get them high up. Thanks for reading this.