O/D issues

[rs2600]

Does this sound like normal operation for the overdrive on the auto trans. It's in i 99 4.0l 4x4.
When taking off from a standstill with very moderate acceleration the O/D shifts in at about 50-55 mph. It then stays in as long as the speed is over 50. As soon as the speed drops to below 50 the O/D disengages even going downhill. Is this normal operation or is there anything that can be adjusted to have the O/D kick in earlier and stay in below 50? I just changed the oil and filter in the trans so its new.
Thanks,
Mats

 

[Glacier991]

The 3-4 shift (OD) is controlled by the computer. A bad input could be your problem - like a bad speed sensor input. Other possibles exist.

 

[rs2600]

So what Your saying is that it doesn't behave properly?
Mats

 

[TPLYNCH]

Are you saying that if you are going downhill and the speed gets below 50MPH, you feel the tranny downshift to 4th? Does this happen if your coasting, foot off the gas?

 

[rs2600]

As soon as speed drops below 50 it shifts in to 4th, downhill or cruising.
Mats