I have a NH 273 haybaler that is creating a serious problem for me. The baler keeps breaking shear pins on the flywheel. I have had a $300.00 service call from the local farm machinery shop, no luck there, I have replaced the brake pads on the twister/knotter, the baler is in time but after I start baling in the field, the shear pin breaks after about every 5 or 6 bales. I winter about 20 cows and I am running out of time to get the hay in the barn. Any suggestions would be greatly appreciated. Thank you