Well, I just replaced my 85 MPH speedo with a 140 MPH speedo. But now I'm having problems getting it to read right. I changed my original 18 tooth gear set to a 23 tooth gear set and it didn't fix the problem. And when I took the 23 tooth gear out today, the gear teeth had been broken while inside the trany during that short period of time. Has anyone worked on their speedo before and experienced something similar to this and found the fix to the problem? Cause I'm clueless at this point....