No 4 Wheel Drive

[muddblood]

Hello. I recently picked up an 01 Montero Limited and the 4 wheel drive is not working. When I first tried it, the lights for the front wheels would flash green and the center differential would flash orange, then all lights would turn off. I checked for vacuum at the actuator and both lines have vacuum, so I replaced the actuator on the front axle. Now, only the center diff lock light flashes and sets ABS codes (haven’t checked codes yet). Thoughts or suggestions on how to get the 4 wheel drive working?

[jkdv8]

It’s probably the switches on the transfer case, front diff switch, or the freewheel clutch solenoid. It’s practically the same setup the sports have with the exception the montero uses 5 switches on the transfer case whereas the sport uses 3.

[muddblood]

It’s none of these. The front axle is not engaging. Vacuum is present and I can see the actuator moving the rod in and out of the axle as the vacuum hose is removed and put back on. Seems like something inside the axle is broken. If I fix it, I’ll probably just put another axle in it (so I can upgrade to 4.90 gears in my Sport 😜😜).

[jkdv8]

It’s at all possible. Have you verified that it’s not actually sending power to the front wheels. With those unless the center diff is locked you wouldn’t be able to tell that it’s in 4 wheel drive by driving it. It would have a similar feel as awd on the sports. Electronic anomalies and throwing abs codes is typical with the switches crapping out.

[muddblood]

Yeah, I had it on the lift at work and no power at all to the front wheels. Even if I “help” them, they do not spin on their own. 4 low works...rear wheels spin much slower. I did however have the abs light come on once or twice when it was trying to engage. I haven’t seen that after replacing the actuator and freeing up the rod entering the axle. I also noticed that the front driveshaft doesn’t spin, but I’m reading that is essentially driven off the front axle??

I know about all the sensors you mention, but they don’t actually control the engaging of the front axle, right? Front axle engagement is all mechanical (and vacuum), right? The sensors only indicate the 4 wheel drive status via the lights on the dash??

[jkdv8]

There’s a switch on the front axle that’s similar to those on the transfer case. It’s used to detect when the front axle is engaged. The switches do however control the solenoid that operates the vacuum for the actuator. They all work in unison though so they all have to function right for the system to operate correctly. So even if the one on the front axle says the axle is engaged, if one of the 4 wheel drive switches or 2wd switch says otherwise then its not going to work right. Also, worth noting that without the driveshaft from the transfer case turning then there is something going on in the transfer case. Throw the e-brake when in 4Hi/awd (however it’s labeled, assuming this is the super select system) and see if it sends power to the front. However given it doesn’t drive the front in 4Lo something isn’t engaging. It sounds as though it’s stuck in awd or 2wd. With the flashing center diff lock light it won’t engage real time 4wd. How everything is activated depends on what all is operated mechanically vs electronically. I also wouldn’t rule out the fulcrum being shot either which hinders shift operation and or the shift forks need adjustments, the latter being unlikely.

[muddblood]

My 99 Sport has had the 4 wheel drive light flashing since I’ve owned it (somewhere around 3 years) and the 4 wheel drive has always worked fine. Even the rear diff lock light would flash when I turn it on an it would work (I fixed the flashing rear diff lock light, so now it stays solid when I turn it on). Since the Montero and the Montero Sport are very similar, and based on what my Sport is doing, this is why I don’t think it’s electrical. Unless the 4wd module is faulty, but I read that hardly ever happens.

The fulcrum, I assume you mean in the 4 wheel drive selector lever, is nice and tight...it’s not loose or binding in any way. I wish there were a way to diagnose this without just throwing money at it.

I honestly feel like the issue is in the front axle. I read somewhere that some Sports (and I assume Montero’s) have shift fork issues. I can manually move the actuator rod and hear the freewheel clutch fork moving inside...but that doesn’t mean that’s it’s not broken (previous owner said the 4 wheel drive was never used by him or previous owner).

And this particular Montero does have the 2 wheel drive option so it is not AWD. My 03 Sport donor was AWD, which is why I opted to keep my 99.

[jkdv8]

I don’t advise anyone to start replacing components but rather a place to start diagnosis. If you haven’t already I would advise you to get a service manual. The sport setup is simplistic in nature. The montero is similar albeit a little more complex with the added 4wd mode. It should have 4 selections, 2wd, 4H (basically awd on the 02 and up sport), 4HLc (basically 4Hi on the sport), and 4Llc (which is 4Lo on the sports).

The bit you mentioned about the front drive shaft not turning points to something in the transfer case, or were you talking about the driveshafts to the front wheels. As for the shift fork anything is possible. I was referring to the shift forks in the transfer case that are operated through the shifter but I wouldn’t rule out the shift fork in the front diff. For a system that was never used I don’t see that being busted though. That sounds more like textbook stuck switches that occurs on the sports as well when the system isn’t used. The problem with the montero is there are two additional problematic switches but it goes back to what all is mechanical and electronic.

[muddblood]

Thanks jkdv8. So the front driveshaft between the transfer case and front axle doesn’t spin when in 4wd. And well, the half shafts coming out each side of the front axle don’t spin either (when up on the lift). You are correct about the shift settings (2hi,4hi, 4lo 4hlc and 4llc or whatever they are). I’ll see if I can source an FDM.

Would it help if I uploaded a video of what the lights do when shifting into 4wd?

The switches on top of the transfer case, they can be removed and cleaned, right?

[jkdv8]

No worries man, glad to help. Yea when in 4wd the transfer case sends power through the drive shaft to the front diff then out to each front wheel.

Do they just flash then go out. If you want. My understanding is that the flashing front wheel indicators should go solid when 4H (awd) is engaged and the orange/yellow diff lock indicator goes solid when either 4HLc or 4Llc are engaged. As we’ve pointed out before what all is electronically or mechanical driven would depend on what is actually malfunctioning.

If you can find the switches cheap enough it may be worth the time and money to replace them. Some are rather difficult to access to be having to remove them to clean and then have them still fail and have to remove again to put the new ones in. You would have to disassemble them to clean and they may not go back together as well. When you see the switches you’ll see what I’m talking about. In this case it really depends on how much your time is worth. They do however typically terminate right next to one another so you can check them while someone works the shifter. Depending on the connectors being easily accessible. All this again depends on what you’re looking for when testing them which would be in the service manuals. There is also typically a lot of useful info in the manuals regarding safety lockouts and tips that can help point you in the right direction.

I know this past time I had the flashing 4wd light it was the 2/4wd switch that failed which seems to be the norm. I’m guessing because it’s always ‘activated’ so to speak because the shifter is in 2wd the majority of the time. Similar to what you’ve experienced with the sports, while the vehicle still mechanically went into 4wd I still got the flashing 4wd drive light with the abs light. With these however there is the possibility that it will not engage 4wd until that switch reads correctly.

[jkdv8]

Also found this perusing the net

4wd.blogeasy.com/ It is based on a non US spec Pajero but some things may be similar.

www.searchautoparts.com/motorage/powertrain-pro-automatic-transmission/cold-and-old-montero-sport-4x4 The bit about Monteros is at the bottom with part numbers. That article is about 4 years old. May want to confirm the part numbers with a dealer according to the vin.

[muddblood]

So I found an FSM online, and I very briefly looked through it and I didn’t see anything labeled 4 wheel drive or transfer case. I checked All Data today and it’s showing a transfer case motor. I’ll check sometime soon to see if All Data is right, and if it is, I can check that motor for proper operation.

For the lights; when I first bought it and got it running, I tried the 4wd system and the front axle lights flashed green and the center diff light flashed orange. Then the anti-lock light can on as the front axle and center diff lights continues to flash. I did some checking and had vacuum at the actuator on the front axle, but I was not able to manually move the actuator or rod. I replaced the actuator and frees up the rod and greases it. It now moves as expected. Now only the front axle lights flash green for maybe 5 seconds and turn off (I think they turn off anyway). Center diff lock does not flash (I’ve only tried 4hi after replacing the front actuator).

[muddblood]

@jk-dv8-so I was talking to one of my coworkers and he suggested replacing the 2wd/4wd switch on the tcase. So based on his suggestion as well as yours, I found all 5 switches on eBay for $27. So I ordered them. They’ll be here sometime between dec 5 and dec 10. I’ll post back with my results. I figure $27 is worth it to rule out the most of the electrical side (I would still need the freewheel clutch switch, which is also fairly cheap)

[muddblood]

So I replaced all 5 sensors on the tcase and now the center diff light blinks orange constantly as soon as I start the truck. Still no 4wd. I’ve read a couple posts (and by a couple, I mean 2) about how to pull the 4wd codes by jumping pin 1 to ground. Does anyone know how to pull these codes??