speedo gear

When you change your speedo gear will that change the shift points for my auto trans . It slides back and forth between third and overdrive at around 45 MPH . I am running 31x1050 BFG's , 3.55 gears. I just ordered a 31 tooth speedo gear to get the speedo reading correctly. Pete

I would bet its the combo of the 31s and the 3.55s thats causing the tranny to search for a gear. Im currently at 30s and 3.55s and mine is having the same problem at a bit of a higher speed. Unless this problem just started after you changed speedo gears thats where i would put my money. With my 30s and stock gears my jeep barely pulls itself up hills in OD and usually always will downshift. Not to mention I cant pull a trailer anywhere because of the tranny constantly shifting from OD to 3. 4.56s here I come!!

Mike