Car not moving... f150 question

for a friend
ok im driving down the 90 in a 1997 ford f150 stepside… an ambulance is coming so i pull over… and come to a complete stop… the amb passes, i try to pull back into traffic and the truck acts like it is in neutral… i put the truck in park turn it off, try again, nothing, i put it in 4wd high and nothing, then put it in 4 low, i hear a loud grinding noise, and it finally goes into 4 low, and the car drives just fine (as fine as 4 low could be on dry pavement without towing anything) the car will not go anywhere in the other 2 modes (4H or 2wd) any ideas what is causing this, im taking the car to a mechanic if i cant resolve it soon… any ideas?

thanks

my guess is the transfercase. have a friend put it in 2hi/4hi in gear and press the gas, see if the shafts are spinning. the grinding i think would likely be a gearset in the transfercase engaging uncooperatively.

a mechanic said something about linkage to him?? in an auto? how would that have broke though? vibrated loose or something?

wait, what kind of linkage did he say?

Probably transfer case linkage if it’s a manual trans case. If it’s pushbottun electronic there is probably a problem w/ the control module or encoder motor. Also check the transmission fluid to see if it’s really low.

yes its a manual transfer case

jump ujnder there while someone moves the trans case shifter and see how the linkage looks.

The Arm to the Case might be bent, it happens a lot on fords but normally on older models. If not the gears are shot from age. how many miles? usually things die slow not abrubtly. If it was electric, i could see this happening more due to bad solenoids.

does it have the 4r70w trans? maybe the manual lever position sensor (mlps)?

not sure… anybody else?

willy go to transmasters in lackawanna. 8268686 is their #. they redid my trans and clutch in about 2 days and i paid like nothing.

97 f150 should be push button 4wd well turn knob