clutch plates could be welded to gather
The A4LD transmission is the most common failure on early explorers. It's very likely that your transmission is failing.
on the bottom of the transmission
This could indicate a simple problem with the vacuum shift modulator or a major failure with the transmission. You will probably need to get it to a mechanic or a shop to get it properly diagnosed.
There are several things that can cause your manual transmission not to shift out of first gear or reverse. The most common cause is a broken shifting fork.
the sunshell gear is stripped out
modulator valve on the transmission.
Mounted on the steering column.
If it is an automatic transmission then your reverse clutch pack is probably burnt out in which case your transmission needs to be rebuilt If it it a manual transmission and it wont go into the reverse gear it is probably a shift synchronizer.
if it is a aod transmission it is on the transmission usually a sensor near the shift linkage .if it is a Manuel it is on the top at the shift tower.
You may have a broken spring which disengages the transmission allowing it to shift or it is bad linkage going to the transmission.
Shift cable adjustment, low fluid, internal transmission failure.
I believe it is on the passenger side of the transmission ( A4LD ) behind a heat shield
Check your Automatic Transmission fluid level
my 2001 ford windstar wont shift out of first gear.
I would look on the transmission by the gear shift linkage.
Some manual cars have a safety built into the reverse shift of the transmission. You need to push the shift knob down, and then over into the reverse gear.
On the vast majority of modern cars today it is impossible to actually shift to reverse while driving at high speed. Modern transmissions have an override safety device that prevents the transmission from going into reverse at any speed forward that would harm the transmission. You could put the selector in reverse, but the transmission would not shift to reverse. On older transmissions without this feature, you would probably destroy the transmission and possible have an accident.
The linkage that connects the shift lever to the transmission could be out of adjustment or the reverse gear in the transmission itself could be bad. Usually it's the linkage.
check the shift linkages for adjustment.there is also an actuator switch on side of transmission will prevent this. if those 2 checks dont fix the problem, your transmission is shot
neutral safety switch is on transmission just below were shift cable connects to transmission
maybe your transmission is going out or you dont have sufficent transmission fluid.
switch on the transmission which sends a signal to the reverse lights when shift is in reverse......... is shot. You need a mechanic.
sounds like the auto transmission has a fault