We picked up a Trimstar Hbar hydro last week since our 48" kees finally went up. We've put 25hrs on it already. Love the H bar, it's fast and puts out a great cut. About 5hrs into it a nut came off making the mower only make left hand turns. I put a nut back on but now the mower jerks both ways. In the manual it says adjust the steering rods. Ive played with them for hours now and still can't get it right. When im cutting a yard I can go one way and literally put my fingers on the safetys and it stays straight. I come back the next way and it jerks from side to side every now and then. Any help on what to do to fix this?