I recently just finished the tranny, its running good, but I still need to do the band adjustment, but before I do that I am going to swap out the tcu, and see if it works. I was testing it and at around 80 it was at 3600 rpm, I think thats alot, is there something wrong? It was never that high.
3600 rpm, 0.694 overdrive, 5187.3198 pinion rpm, 3.70 to 1 ring and pinion ratio, 1401.9783 axle rpm,
stock tire on a fwd, 225/50/16, is 24.86 tall (when new).=9124.5333 ft/min, or 1.7281313 miles a minute, or 103.68787 mph?
3600 rpm, 0.694 od, 5187.3198 pinion rpm, if 4.11 gears, now its 1262.1216 axle rpm,
24.86" tall tire, now 8214.3001 ft/min, or 1.5557386 miles a minute, or 93.344316 mph?
The spedo does not know if you have worn tires, and worn tires would have no effect on the relationship between spedo ant tachometer.
If its NOT slipping, and you can feel the shift from first to second, the shift from second to third, and the shift from third to fourth. The only other "shift you have to feel is the transmission torque converter locking up.
If you have all that, and you check the accuracy of your spedometer with a stopwatch and several mile markers, ( at 60 mph they should go be at exactly one minute intervals ), then, I would guess that the TPS was out of adjustment.