RedHat
Guest
I think the double drive versions started in 1993_94, but that won't fix your problem. The bar back breaks due to the rear stabilizer bushings being worn out. They are located at the rear left hand side of the header where the two grease fittings are with the 10 hours decals. When these bushings are worn the frame that the wobble box is mounted to will start to move laterally with every stroke of the knife. When this happens the frame tries to stabilize through the bar back at it breaks. No matter how often its rewelded or the bar replaced it will keep breaking until the bushings are replaced. The header will shake badly when the bushings are worn, check with a prybar at the outside mount and pry down on the nut. If there is any movement at all it's toast.