Super Select 4wd System.
Posted: Mon Nov 17, 2003 5:49 pm
Ok lots of people have asked this question and fair enough to, the Mitsu super select system can originally appear complicated and hard to understand but once you look at it in depth it's a fantastic piece of automotive engineering. But it does have it's problems mainly with the dreaded flashing light syndrome which is usually linked to an electrical issue.
Basically the front diff is permanently locked to the left hand (shortest) front driveshaft.
The right side driveshaft is disconnected from the diff but will spin because it's locked to the wheel when in 2wd.
So in 2wd both front driveshafts, diff and propshaft will all spin when in 2wd.
There is a vacuum operated free wheeling hub that is attached to the right side of the diff housing. When 4wd is selected vacuum pressure is released from the vacuum storage cannister (located on the right side of the diff housing) which allows the piston to extend engaging the free wheeling hub. This locks the right side driveshaft to the front diff.
If the ignition is switched off engine vacuum is depleted and the piston will retract diengaging the free wheeling hub so the right side driveshaft will be disconnected from the front diff.
Remember there are no manual hubs on this system just wheel hub flanges which bolt the driveshaft to the wheels.
The fitment of manual hubs will prevent both front driveshafts and diff permanently rotating when in 2wd.
There are 2 electrically operated solenoids (located on the drivers side wheel arch in the engine bay) which feed/vent engine manifold vacuum to the free wheeling hub located next to the front diff.
My advice to Paj owners who are confused about this system is to buy a Gregory's no 510 as it explains it quite well.
Also the fitment of manual hubs will extend the life of the front running gear (CV's, boots etc) especially for those that have cranked their torsion bars to achieve more ground clearance.
If there is a mechanical problem and you loose front wheel drive (when in 4wd) you are the same as if a part time system has malfunctioned.
Manual hubs gives you a little scope here if you blow a front CV you can disconnect that hub to stop the driveshaft spinning when in 2wd.
Any Aisin type manual hub found on early or base model Paj's or Triton will fit onto a super select Pajero. It's a 20 min job, just unbolt the hub flanges and bolt on the manual hubs.
Also a NM onwards (Gen 3) Pajero cannot have manual hubs retrofitted as the hub flange is one piece (ie - not bolted to the wheel hub).
Basically the front diff is permanently locked to the left hand (shortest) front driveshaft.
The right side driveshaft is disconnected from the diff but will spin because it's locked to the wheel when in 2wd.
So in 2wd both front driveshafts, diff and propshaft will all spin when in 2wd.
There is a vacuum operated free wheeling hub that is attached to the right side of the diff housing. When 4wd is selected vacuum pressure is released from the vacuum storage cannister (located on the right side of the diff housing) which allows the piston to extend engaging the free wheeling hub. This locks the right side driveshaft to the front diff.
If the ignition is switched off engine vacuum is depleted and the piston will retract diengaging the free wheeling hub so the right side driveshaft will be disconnected from the front diff.
Remember there are no manual hubs on this system just wheel hub flanges which bolt the driveshaft to the wheels.
The fitment of manual hubs will prevent both front driveshafts and diff permanently rotating when in 2wd.
There are 2 electrically operated solenoids (located on the drivers side wheel arch in the engine bay) which feed/vent engine manifold vacuum to the free wheeling hub located next to the front diff.
My advice to Paj owners who are confused about this system is to buy a Gregory's no 510 as it explains it quite well.
Also the fitment of manual hubs will extend the life of the front running gear (CV's, boots etc) especially for those that have cranked their torsion bars to achieve more ground clearance.
If there is a mechanical problem and you loose front wheel drive (when in 4wd) you are the same as if a part time system has malfunctioned.
Manual hubs gives you a little scope here if you blow a front CV you can disconnect that hub to stop the driveshaft spinning when in 2wd.
Any Aisin type manual hub found on early or base model Paj's or Triton will fit onto a super select Pajero. It's a 20 min job, just unbolt the hub flanges and bolt on the manual hubs.
Also a NM onwards (Gen 3) Pajero cannot have manual hubs retrofitted as the hub flange is one piece (ie - not bolted to the wheel hub).
