170 steering question

I have the early model 170 with the rack and pinion which turns the steering arm. The teeth on the shaft, and the arm are both very worn. At some point it's going to give out. When it does, I've thought of removing the arm and converting it over to something similar to the later 170/175 by building a single tie rod with screw in ends and adding a hydraulic steering cylinder and connecting that to the hoses from the orbital. Anybody ever do that? Reasons why it wouldn't work?     

Thanks for the advice. I was wary of welding it but will give it a try.

Yep. When I discovered the problem the roll pin was broken and the arm hanging down. Judging by rust and dirt on broken pin it was that way for a lot of years before I bought it. Tie rods were worn out and I replaced them, which had to be a factor. It will break a new pin, so I have a smaller pin driven into the larger one to re-enforce it. Good winter project to fix the right way. I wont use it too much until then. Thanks again!