Sunday, Jan 28, 2007 at 21:03
Oops, wrong key pressed.
When you push the button on the dash, you should be moving at up to 80kph, and a clutch in the transfer case is brought into play. This clutch will engage at various pressures from 0% to 100% giving giving up to 50% of available drive to the front diff (hence 50% front, 50% rear). In addition to the transfer case clutch being engaged, a clutch on the left front axle is engaged to lock drive to the front wheels.
There are no hubs that lock in. When you go into low range, the clutch is locked in place by a ring gear and there is no variation in % drive to the front, you get 50% front, 50% rear and low ratio.
The problems that can occur are -
1) The transfer case solenoid does not engage and the clutches therefore don't work. You will have flashing dash indicator. Repair might involve replacing the solenoid which unfortunately involves removing the Gearbox. I know this because
mine was done under warranty - apparently the solenoid comes out via the top and/or the wiring loom is impossible to release with the gearbox in place.
Mine's auto - I'm not sure if the same applies to a manual.
If this is the fault, the front clutch won't attempt to engage, so you will have 2wd only, even in low range.
2) The front axle clutch doesn't engage - again you will have flashing indicator. This is both vacuum and electrically operated so a good
check and clean will mostly overcome a problem in this area. If this doesn't engage, you will also only have 2wd, even in low range.
3) You may have got the TOD computer wet - it's under the drivers
seat and is not sealed - remove it and give all the connectors a good blast with electrical contact cleaner and re-assemble.
If you are not moving when you press the button, the front axle cannot engage its spline - from memory, the system tries about 3 times per second for 5 or 6 seconds befoe it gives up trying to engage and will also set the indicator flashing.
Of interest also is the fact that when all this is engaged, the front axle clutch will disengage if the front wheels are near to full lock to prevent damage to CV joints.
The system is by Borg Warner, and is fitted to a number of other makes as
well as Jackaroo. Needs to have ABS to work, as the TOD front wheel slip sensing is done by the ABS sensors
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