shifting problems

[Abscess]

(4spd OD) drove about a half hour out then in second gear I couldn't shift into 3rd tried 4th to no avail went about 2 miles in 2nd. stopped at mom's 5 minutes than I checked I could shift (cold) into each gear. about anouther 10 minutes from cold I had some resistances shifting cold but then no problems working through the gears 5 or 6 times. Coming home was the tricky part. Over the highway up over two highways over the mountains. So trying not to downshift before an up climb and down shifting before an upclimb. Even getting ble to shift into 4th onto HW then I had to slowly aaccelerate from 35mph in 4th gear over 2 miles. This is what I had to do to insure I might climb over a rate that I might have used a 1/4 tank to climb the mountain without/od but descending with OD. I climbed up over another small mountain and down in 3rd gear. Over all shifting problems seems while hot not cold.

 

[RonD]

Trans fluid is thicker when cold.
Automatics work on pressure, there are no "gears" that mesh together.

The pressure holds trans in the "gear" selected, if there are leaks in gaskets or passages then pressure can change enough to cause mis-shifts or no shifts.
If symptoms start after trans fluid "thins out", when warmer, then leaky gasket or passage would be my guess, but just a guess.

The only "simple fixes" I have ever encountered on an automatic are loose shifter linkage cable/bar and leak in the pan gasket.
Everything else has been pull it and replace it or rebuild it

 

[enjr44]

Is this thing an automatic or manual?? From your description, I can't tell for sure.

 

[McCormack]

If it's an automatic, the vehicle speed sensor, which is located in the rear differential (on my 2000 it is anyway) might be the cause. A couple of years ago my truck started having shifting problems (up shifted way before it was supposed to and then wouldn't down shift), and replacing the speed sensor cured it.