97 F150 4x4 4.6,

I was driving about 60mph, and went down a hill, so I was coasting till the bottom of the hill, when I started to accelerate again I was only revving the engine, I was still in drive, but basically in neutral. I pulled over immediately, put the truck in park, and then back into drive. I took off, I quickly realized my engine was running normal, but I wasn't accelerating much. I eventually figured out, I was in 4 LOW. My shifter on the floor was still in 2HI.

Now I bought the truck used, the body has about 300k on it. The 4WD never worked, it was a work in progress to get it up an running properly.
My transfer case was clogged up with junk when I bought my truck, mechanic been blasting it out and it is now functional, to the point when I can move the shift lever to all positions. I was always able to get it to where 4HI was, and it would say 4x4, but never actually do anything. Now all it ever says , in any position is 4LOW.

I had stopped somewhere and had a mechanic look at it on my way home, driving 20mph all the way , unfortunately he is too busy to work on it and my mechanic is on vacation all week. But this gentleman was kind enough to put it on a lift and take a peek and a quick drive. He says it does sound like its stuck in 4LOW, although the front axles aren't engaged, he saw everything sliding properly when shifting the lever, but no actually engagement, just a lot of clunking noise if you do it while driving.


All that said, I cannot try to go into 4HI, because it just says 4LOW where HI should be now. And I'm stuck waiting. Is there anything I can do to get it out of 4LOW, or should I just not bother and let a professional look at it.

Thanks again.

 

You need to know how the system works in order to know what the cause is.
Normally you would need to be stopped, in neutral and foot on brake.
You see these three requirements for 4L.
There is a module that controls the system from these inputs that all must be present at the same time.
The only way for uncontrolled 4L is if the module has a fault.
Very often the windshield leaks onto this module, causes conductive corrosion on the circuit board.
When this happens in your case, it cause the transfer case motor to go to the 4L position.
This engages the lower gear drive from the case..and..changes the transmission shift schedule so the motor RPM vs road speed is back to normal in the lower gearing.
You see anyone who is going to work on the system has to know these things in order to see at what point in the chain the fault is.
Unless someone has butchered up the control wiring to cause additional issues, this should be able to be solved.
The Module is called a GEM and is programmed to your vehicle build so has to be with proper internal program.
Good luck.

 

He says he has a manual shifter though. Way different than an electric motor. I would think it's internal to the t-case. It's not hard to find these in junkyards.... especially you pull it lots like LKQ. (Everybody wants the trans but leaves the t-case)

 

I think if it is manual, it still signals the transfer case motor to shift things inside.... Take the transfer case electric motor off the side of the transfer case. Manually rotate the shaft to get the insides back into the HI position. unplug the motor wire and reinstall to plug the open hole.... You can run like that until you want to fix the 4 x 4.

 

Manual means no motor. The shifter physically changes the gears in the transfer case just like a manual transmission.

 

well, that could be, but HOW did it switch gears without someone moving the rods ? I don't know, just wondering if the "manual" shift moves switches that signal the motor ?
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--either way, if it has a manual plate over the area where the shift motor is, you can remove the plate and turn the internal shaft back to HI position............ something had to move the internal shaft.

 

There is no shift motor. It's a shift lever that goes straight into the tcase with some linkage. You either shift it into 4l, or perhaps a fork internally failed, dropping it into 4l. When things break they have a tendency to do whatever they want. In this case, go to 4l

 

so step 1 is to remove the cover plate and try to move the lever by hand, or see if it broke off. Should not be too hard to remove the cover and quick look.

 

Not sure what cover you're talking about. There's two case halves, and splitting them requires major disassembly.

 

in the case the same as the electric unit ? I assumed there was a cover over the area where the transfer case motor is normally mounted with a rod/ arm sticking out ? On the motor operated units, you can remove the motor and try to turn the shaft by hand (tools) to see if it moves. I agree if something is busted inside, your toast. If the shift lever is in HI and the case is in LO , I would check to see if something slipped or moved on the outside or linkage........... or internal busted.

 

Different case