Hmm...all very good ideas. I will open it up when I get a chance to see if it is just set screwed in. But, it it's not set screwed in, I think I'll try the coupling idea and weld it at both ends. The only slight hesitation I have is that these two rods are going to be under a lot of stress most of the time. That is why my first option is just to replace the entire shaft. But if I can't, I think that the welding job might do. Wait, no, I can't do the welding, I would be able to screw it in though. Because, I am putting a bearing on the shaft and bolting it to a steel plate, and I wouldn't be able to put it on if I had the coupling. I could however weld the extension on after I mount the bearings and motors onto the rig, but then I would never be able to remove the motors. This project is going to weight upwards of 1,000 lbs, so, I just want it to be as strong as possible. Again, thanks for the suggestions guys, and any more options are welcome.
Thanks
Mitch