The root cause of my 4WD engagement issues on the NL Pajero

I seem to have diagnosed the root cause of the 4WD engagement issues on my NL Pajero. The two vacuum lines that drive the engagement/actuator rod in and out of the front differential appear to be being "driven" inconsistently by the vacuum solenoids.

[@mezje]

The NM has the exact same issue with those solenoids! You did a lot more deep diving than I did. I just googled it and replaced the solenoids! Nice and easy, under the airbox on an NM from memory...

[@KaldekBoch]

Yeah same place on this AND my '92 NH.

[@tawhiricook2328]

Mate thanks for the vids, mine has just decided to jam in 4h can’t move lever at all will check my actuator and solenoid,

[@KaldekBoch]

Hi, I missed your comment at the time you posted it. I assume you discovered that your lever shift ball had disintegrated?

[@riskset]

Great vid

[@righthand7965]

How's it all going? New video? Hanging 🙏😊😊👍

[@BigBalls100]

Cheers mate

[@merchanthandson5271]

I have question. What is the oil under radiator of this pajero same unit. There were two small pipe left and right of my radiator.

[@KaldekBoch]

I'm not sure what you mean? Can you describe in more detail please.

[@ladytradiej8027]

Did you end up making the solonoid video?

[@thatodang]

SOLENOID

[@on1ytheb3st]

Do the NLs have a viscous clutch system in their center diffs for Full-Time 4WD (4HI) or was that not seen until Gen 3 Pajeros when Super Select II came out?

[@KaldekBoch]

Yes it has the VCU for 4WD mode. Pretty much all Mitsubishi AWD systems including Lancer Evos used VCUs. 4WD Lock mode doesn't use the VCU of course.

[@on1ytheb3st]

@@KaldekBoch finally found some articles detailing this somewhat. So in 4H the open center diff works in tandem with the VCU which distributes power ideally 50:50. When the center diff is locked it BYPASSES the VCU. Do I have this correct?
I know a lot of modern systems like Volkswagen’s for example employ just a Viscous coupler (no center diff) to mimic both an unlocked and locked center diff by altering the fluid properties.

[@KaldekBoch]

@@on1ytheb3stYeah, the "open diff works in tandem with the VCU" is how the other Mitsubish AWD systems work too. Some newer systems used "Active Center Differential" aka ACD, which removes the VCU and replaces it with computer controlled clutch packs much like how AYC works for the rear diff in stuff like the Evo.
I guess "bypass" isn't the right word for 4WD-Lock as it's, well, just locking the diff. Once the diff is locked the plates within the VCU aren't sliding past each other.
Fun fact - on the Lancer Evo the center diff is in the gearbox itself and the VCU or ACD system is inside the transfer case. Whereas with the Pajero, the center diff is indeed inside the transfer case along with the VCU.

[@on1ytheb3st]

@@KaldekBoch Right okay that makes total sense. The VCU reacts when there is a large difference in driveshaft speeds by shear thickening the fluid but if the driveshafts are locked together they never spin at different speeds so the VCU never engages.
I’m still breaking things down conceptually so I’m not too familiar with the differences of a Transfer case and open differential. I understand the purpose of an open diff but people use them interchangeably sometimes.
I’ve got a older (R50) Pathfinder with the the “All-mode” transfer case and that’s still a great mystery to me in its function. I know it has a VC but it’s distribution of power and when it’s done is not easily found info. In Auto mode I believe it sends power to the front during acceleration and when there is slip in the rear. And I believe it does truly lock into 4H but there is no term for center diff in the FSM, just the ATX14A transfer case. Do you think the Viscous coupler physically can lock too?
Edit: did a little more research and it sounds like the ATX uses a “wet clutch pack” so not quite a viscous coupler. In 4H it’s not a true geared engagement. It spins the hydraulic control for the clutch to 100% is all. Sounds like it’s still dependent on the friction of the clutches to maintain 4H unlike the physically locked center diff of Mitsubishi’s Super Select.

[@KaldekBoch]

@@on1ytheb3st Nissan has a whoooole different approach to torque splitting. Just look at the ATESA system in the Sklyline GTRs (R32-R34 at least). Their system has controllable torque split. Mitsubishi is more like Subaru here: full-time AWD with 50/50 torque split, and a VCU or clutch packs to limit slip.

[@thomasmacokatic6219]

solo??