In my 1990 Bronco.. one of the few mechanical problems remaining with this vehicle.

It doesn't do this until I've driven it 10-20 miles, it will wait until about 3,000 RPMs to shift regardless of throttle, when it does shift it shifts pretty hard.. the hard shift might be because of the feeling of a late shift, but I'm not sure, it feels a bit harder than it should shifting at 3k RPMs. It's a lot worse up hill, I get to the top of the hill after being in second and it feels like the tranny is going to throw itself out of the vehicle. When I feel the shift into third coming, I have to let off the gas to lessen the kick.

I don't know if it's related, but sometimes when I let it sit and idle I get a weird whining sound out of my transfer case.. for the longest time I thought it was a failing fuel pump (almost the same kind of sound) until I tracked it to my transfercase. It usually happens if I go WOT while in park or neutral and then let off, then it will go away when I put it in gear and wont make the sound again.

otherwise the transmission feels great, shifts fine up or down, stays in gear, locks up when it should.

 

how fats are you going at 3000rpm before the hard shift?