Tweet
Hi folks, I’ll apologise in advance for the long winded story - hoping someone can point me in the right direction in relation to a problem my young bloke having with his ML Triton and the front diff freewheel system. I have read heaps of posts on this site that addresses the common flashing lights problem and while those posts have been very helpful in understanding how the system works, unfortunately our problem persists.
A coupe of weeks ago, whilst driving in 2WD, the 4WD lights on the dash started flashing and was accompanied by a knocking sound coming from the front diff area. The problem seems to solve itself by cycling the 4WD shifter into 4WD and then back into 2WD (sometimes once - sometimes 2-3-4 times or more), at which point the lights go off and the knocking noise goes away.
So on checking it turns out the front diff actuator was extending half way towards the “freewheel” (2WD) position, causing the knocking noise inside the freewheel assembly. Things we then checked include:
Vacuum - confirmed holding vacuum (including checking vacuum accumulator canister - all good / all vacuum lines checked - all good).
Actuator - swapped over identical part from a Pajero which confirms actuator was working properly.
Vacuum solenoids - bought a new pair online and installed.
So after many hours testing everything and after installing the new solenoids the problem persists. We have jacked the front of the vehicle up and if we cycle from 2WD to 4WD, the actuator does what it is supposed to do however will eventually (could be anywhere from the 3rd cycle through to about the 10th cycle), will only extend (or retract) to about the half way point which immediately makes the 4WD lights flash and if we spin the wheels, generates the knocking noise from inside the front diff freewheel assembly. This initially suggested to me that we were losing vacuum but I don’t think it is for 2 reasons: 1. If I cycle the 4WD lever again after the fault occurs, more often than not, the actuator will then extend (or retract) fully as it should do; and 2. When the fault happens, we have checked vacuum on the inlet side of the solenoids and it is still there. This leads me to suspect we have some sort of intermittent electrical supply problem to the solenoids which is causing them not to open when they should??
I haven’t checked the transfer case switches - I’m not sure whether a faulty one (or two) would cause this sort of problem??
Any thoughts / advice would be much appreciated.
Cheers
Scott
A coupe of weeks ago, whilst driving in 2WD, the 4WD lights on the dash started flashing and was accompanied by a knocking sound coming from the front diff area. The problem seems to solve itself by cycling the 4WD shifter into 4WD and then back into 2WD (sometimes once - sometimes 2-3-4 times or more), at which point the lights go off and the knocking noise goes away.
So on checking it turns out the front diff actuator was extending half way towards the “freewheel” (2WD) position, causing the knocking noise inside the freewheel assembly. Things we then checked include:
Vacuum - confirmed holding vacuum (including checking vacuum accumulator canister - all good / all vacuum lines checked - all good).
Actuator - swapped over identical part from a Pajero which confirms actuator was working properly.
Vacuum solenoids - bought a new pair online and installed.
So after many hours testing everything and after installing the new solenoids the problem persists. We have jacked the front of the vehicle up and if we cycle from 2WD to 4WD, the actuator does what it is supposed to do however will eventually (could be anywhere from the 3rd cycle through to about the 10th cycle), will only extend (or retract) to about the half way point which immediately makes the 4WD lights flash and if we spin the wheels, generates the knocking noise from inside the front diff freewheel assembly. This initially suggested to me that we were losing vacuum but I don’t think it is for 2 reasons: 1. If I cycle the 4WD lever again after the fault occurs, more often than not, the actuator will then extend (or retract) fully as it should do; and 2. When the fault happens, we have checked vacuum on the inlet side of the solenoids and it is still there. This leads me to suspect we have some sort of intermittent electrical supply problem to the solenoids which is causing them not to open when they should??
I haven’t checked the transfer case switches - I’m not sure whether a faulty one (or two) would cause this sort of problem??
Any thoughts / advice would be much appreciated.
Cheers
Scott
Comment