I have a LW 4000 that works wonderful for the first wash. Second customer deposit money, press button to select wash and Auto Cashier go to Wash Busy. The boom has flexed back and is blocking the back eye on the T bar. Push it slightly forward light kicks on and ready to wash. This doesn't happen every time, but way to often for me. I thought the L frame was bent so I replaced it, no difference. Checked ball bearings all good. I hope someone can help guide me, what am i missing?