rear diff lock

[cssuk]

hi all i have a patrol 4.2 petrol auto with rear diff lock however the diff lock wont work, tried it on the loose in 4lo clicked the switch nada no lights noises etc so i need to know where to start are there actuators as i assume its air/vac operated? any relays or solenoids anywhere that need looking at? am thinking electrical initially as i get no response whatsoever to the switch even when parked up ign on others i have looked at i could hear something click not on mine. they were also petrol

ta

 

[andrewk]

the diff lock wont work, tried it on the loose in 4lo clicked the switch nada no lights noises

When you turn the difflock switch, you should get a flashing "Difflock" light. Once the diff has actually locked, the difflock light is on continuously and the ABS light flashes, as ABS is disabled when the diff is locked. If the difflock light doesn't flash, you've have an electrical problem you need to fix before you do anything else.

The difflock is vacuum operated, if you stick your head underneath, you'll see the actuator on one side of the diff. The actuator has two vacuum pipes going to it - one going to each side of the actuator diaphragm. When the pipe nearest the diff has suction, it locks the diff - when the other has suction, it unlocks the diff. The vacuum is controlled by electrically operated solenoids, which are under the bonnet (near the bulkhead) on the kerbside of the 'Troll'. There are two solenoids in the block you see there - one connected to each pipe (the ones that go to the actuator on the diff). In one position, the solenoid opens the pipe to air - and in the other, connects it to the vacuum reservoir (which is directly under your chin if you are leaning on the wing and looking at the solenoids).

You could do with the relevant pages from the workshop manual to make a start on fault finding. The bits about the difflock are in a file pd.pdf which is about 2MB. If you haven't got a manual, send me a pm with your Email address in it - and I'll send you a copy of that file (for the Y61).

Cheers
Andrew

 

[nellie]

Diff lock

Hi cssuk,
I had the same problem on nellie,
As andrewk says the actuator is on the right hand side of the rear diff.
Follow the pipes all the way to the engine bay checking for any damage.

Plus take of the pipes to the actuator at rear, and try and push a piece of
wire down the pipes that go directly in to the actuator, you may find that the steel has rusted & therefor expanded, thus blocking the pipe.

As for the light on the dash, mine stopped working ages ago but the diff lock is fine,but could also mean your diff locks not working.

When i went to nissan peterborough and spoke to a chap named bob,(service manager) and said i,d broken my diff lock he said no way, unless youve done something silly.

I didnt beleive him of course, silly me.

Hope this helps.
Nellie.

 

[BIGBADWULF]

could be something as simple as the wiring plug is off the switch?

as it got an after market radio in it? if so when the dash panel is
removed to fit it perhaps the plug not refitted???

when it is working you should be able to hear a clunk from the
diff when operating the switch. on the Y60 models, the light is either
on or off, no flashing. it comes on when locked in and goes off when
out. there can be a delay there

 

[cssuk]

thanks for the replies but yes the clunk you refer too is missing so thats what makes me think electrics initially as no relays solenoids etc can be heard i will of course follow it back from the pipes and see how i get on but i suspect its electrical to be honest so solenoids switchs and power first is it vac operated or positive pressure operation? if positive is there a pump somewhere or is it a changeover solenoid?