Started playing with the D4H LGP last week. After a few hours of rather vigorous dozing, noticed the blade was unstable and frame towers were hitting the engine screens. Inspection showed the C frame was broke just to right of blade pivot pin. Further inspection showed it had been previously repaired and the weld looked like swiss cheese. Had been ground down, filled with bondo and repainted. (what a jerk of previous owner) Started looking for frame for the 9GJ unit with some success although prices were tough. Found a shop that can install new sections and weld for seemingly reasonable price. Has someone been faced with this repair and have suggestions. Looks like the Mitsubishi folks used minimum quality steel. The used correct part number (8E9990 ?) frames were in $3200 plus price range while the repair was one half cost. By the way, was amazed by the work the 125 HP rig could do.
The Part Number you have (8E9990) is correct, as is the price range for a new part. I found nothing specifically relating to field repair or reinforcement of that particular Part Number but there are a couple of more generic documents regarding C frame repair and/or reinforcement. If you want them just drop me a PM giving me your email address.