Departing Bullwhacker I found I needed an unusual amount or right rudder to keep the ball centered. I came around and landed again to check it out. When we pushed my plane back Sunday night the elevator hit some sage brush. So we assumed that something got tweaked back there causing an out-of-trim condition. But we looked and compared and looked some more and couldn't see anything that was bent. At least I knew I didn't have anything drastically wrong back there. I took off again but still needed a lot of rudder to fly straight so I landed at Knox Ridge. This time I also looked at my nose gear and discovered that the head of a torque link pivot point bolt was gone. The bolt was still in place but no hex head. I wrapped some safety wire through the cotter key hole to keep it from falling out. I was planning to go to GTF for fuel and I'd get a bolt there. But as I got closer to GTF I could see low clouds ahead. I called FSS and was advised that GTF was IFR. So I diverted to Big Sandy where it was good VFR yet. I bought fuel from Tom Hlavnicka who runs a spray operation there. I got a bolt from him. It was still socked in to the west so I filed IFR for FCA and punched through 3 layers up to 12,000'. FCA was VRF. There was some ins and outs in the clouds at 12,000' but no ice over the mountains The broken bolt was allowing my big nose wheel to cant a little and throw the rudder trim out of whack. The trim was fine with the new bolt in place.