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Retrofitting a Factory Air Locker into a Gen-II Montero/Pajero

Can I mount the complete Mitsubishi system?

Yes, but know that electric parts are different (or at least located in different places) from LWB/SWB, from '94 and earlier/'95 and later (depending on where they are sold). My electric parts came from a '95 SWB and fitted in my '97 LWB. However, do this simple check: remove the little plastic cover at the left of the electric plug (the one in the dash, under the radio bay) and you should find a little connector.

What do I need?

-Mitsubishi axle, or at least, the 3rd member and the left axle shaft
-Mitsubishi air compressor, or any 12v compressor with a pressure limiter (my locker engages from 0.9 to 1.2 Bar, maybe less when installed and filled with oil...)
-Mitsubishi dash switch
-Mitsubishi locker ECU
-Mitsubishi electric cable from locker sensor to body, or any 12v cable and some cut and paste...
-2.5m of air line.


Once the parts are in place...

The whole work can be done in a day, but you should decide to do the 3rd member swap one day and the other work later. Uh, 3rd member swap? Yes, not a complete axle swap. My main reasons were:
- I wanted to check the used diff before installing
- I didn't want to disconnect (and purge after reconnecting) brake lines (and I was wrong, left axleshaft must be replaced...)
- In the used axle many parts were missed (brake lines too) and the handbrake cables were cut
- Air line and sensor fittings were in the 3rd member, so no mods were required to my axle
- I'm not sure, but a complete axle swap should require more work and effort...

3rd member swap
- park your truck, in 1st low, with the center differential locked - don't engage your hand brake
- raise your truck from the axle, and place jack stands under the frame (uh, there aren't jack stand in my photos...)
- drain the diff
- pull tires
- unbolt and remove brake caliper (without disconnecting brake lines)
- unbolt and remove brake rotors (maybe you have to bolt something in the holes to take it off)
- unbolt and pull out for 10/15cm axle shafts
- unbolt and remove the drive shaft
- unbolt and remove 3rd member - a couple of notes: the unbolted 3rd member will stay stuck in the axle, so start prying it out with a big screwdriver starting from the lower left quarter (looking from the front): near there you should be able to find a place where you ca insert the screwdriver between axle and 3rd member - pay attention, the 3rd member is quite heavy, having your sway bar installed can help you.

Repeat (where needed) the same operation for the donor axle- when you have both 3rd members apart, check by hand if they have approx the same freeplay - more, check if the locker works (don't use too much pressure) and if the sensor works. Don't remove the sensor (unless it's broke...). If you simply re-bolt it in, you partially lock your differential reinstalling the sensor without removing the carrier from the 3rd member requires a lot of patience and a bit of magic... As you can see from photos, the locking mechanism uses square teeth, but there is some sort of syncro gear too hidden in the carrier.

- clean the axle housing, and the old loctite
- put new loctite on the 3rd member, insert it in the axle housing, and re-bolt
- remove axle shafts, at least the left one- the Mitsubishi locker uses a shorter (+-15mm) left axle shaft - the right axle shaft is the same length
- removing axle shaft requires removing the park brake cable (and removing the park brake cable require disconnecting brake lines...), so I've replaced only the left one

Now it's obvious, you have to reinstall all the removed parts. Don't forget to refill your differential with oil, not for LSD.

Now install the other stuff.

Dash Switch

Remove the little plastic cover at the left of the electric plug (the one in the dash, under the radio bay): you should find a little connector - connect the switch and press it in the hole.


In the LWB the compressor must be installed under rear seats, right side (where you can find the jack). You should find a little (2 wire) connector. Note: this connector sends power by command of the locker ECU, so you can install a common 12v air compressor with a pressure limiter (I think 1.2bar is still a safe limit, since I've pumped my diff up to 2bars to check for leaks).

Locker ECU

This is hard (can we say PITA?). In the LWB the connector is located in the rear left quarter of the car, and my Paj has the 3rd row of seats... So first remove the left seat, then the big plastic cover. I know, it's a lot of work, at least 15 bolts to remove. Now you can find an hole near your rear left corner. The connector is somewhere inside this hole... In my Paj there is another hole, filled by the seat belt roller, and if you have little hands maybe you can try this way - however for me it was pretty hard to take off the connector. Once you get the connector, remove the plastic cover on it (it has a wire for short-circuit some thing) and plug in your locker ECU. Then you can reinstall everything (if you can remember where all the bolts go...).

Mitsubishi electric cable and air line

Pretty easy, but you must go under your car once again. Of course, one side of the electric cable must be connected to the locker. The other connector is on the frame, near the lower arm front bushing. Now the air line. As I installed it (and the electric cable follow it), it starts from the locker, then goes to the rear of the axle, follow the lower arm and then enter the car under the rear left wheel well. You can see a rubber cap with some wires coming from it. I've simply made a cross cut in the rubber cap and pressed the air line in it - now reaching the compressor is easy.

Locker light on the dash

If everything is well connected, the locker light automatically lights up every time you turn the key, and every time your locker is locked.

On-board Air - yet again...
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