transmission problem

i srevice my jeep 1 weeks ago, and saw little aluminium shavings in the pan. i noticed that it shifts from 2-3 around 3000-3500 rpm when cold (below freezing). shifts beter when the jeep is warm or when its warm outside.
the fluid is full 3/4 up the hash marks. was woundering if i should adjust the front bands buy turnig the that little screw?
thanks for the help
bryan

That sounds normal to me.