Hi there, ive been having problems with the trans in my 96 bighorn for a while now. Mainly after ive taken it out of 4wd upon reacing the tarmac again, when i get up to around 100k it seems to run out of gears. At 100k its pulling around 4500rpm. Ive tried stopping and shutting off for a few minutes but when i take off the problem persists. After a while of cruising along at around 90k, at any random time or distance it will all of a sudden change up about 2 or 3 gears within a couple of seconds and will now happily sit around 2000rpm at 100k. Also, even after not being offroad for a while if i put it in o/d at 100k (2000rpm), it shoots up to about 3500-3700 and almost seems to slow down? Ive taken it to a workshop where they gave the trans a service but it made absolutely no difference. Any Ideas?