NamesTM

I have a 88 ford f-150 XLT with a 5.0 motor, A few months back my rear end started to act up, I pulled out my Ring and pinion, Spider gears, and carrier, and replaced them. Now that I have everything working my transmission wont shift, It goes into Reverse, Neutral, and Drive, but never shifts out of the lowest gear. Before my rear end went out my transmission worked fine.

The things we have done to trouble shoot the issue.

Checked the transmission fluid and was low 2 quarts, so we filled it back up with transmission fluid.

We checked for a Vacuum Modulator but has none to find, It appears to be all electronic.

We have tried driving it down the road, putting it into neutral and back into drive but nothing changed.

Thanks: Thomas Wilkins.

chipset

Unless you have a tone ring in your diff. and replaced it with one that does not there is
no way a gear change will stop your transmission from shifting. Are all wires connected ?
is the V.S.S. connected ? Does the speedometer work ? If you ran your transmission 2
quarts low it's probably burned out. My wife ran her's 1 quart low and it is done and it too is electronic. Need a lot more info. What happended from the time you changed the
diff till the time the transmission went out ?