Centre diff lock stuck on

[synthium]

Hi can't get the centre diff lock off. The gear stick moves to off easy enough. I have reversed and moved turned in circles backwards. Jacked up a wheel and did it again. And again and again. Tried driving fast and braking. Also tried changing when moving. Is there any other tips or tricks? This isn't the first time it's happened but usually one of the above works eventually. I have been trying for a few hours now! Help appreciated!

[workingonit]

Is the light on the dash constantly on, if yes, then check sensor is clean, not screwed in too far or not screwed in enough. If the light goes off, but you are getting vibrations or other indicator it is not disconnected then some physical component has let go or broken or worn out ie check linkages, take diff lock case off and inspect etc.

[synthium]

Light on the dash is on but can defiantly feel it's on, especially when turning. Also when wheel jacked up it will only rock back and forth suggesting the diff is engaged from what I understand.

[synthium]

Are there any good guides with pics to taking apart diff lock

[synthium]

Ok so I have been under the defender while my assistant moved the centre diff gear stick in and out of lock. Defiantly engaging and disengaging on top of the diff but obviously something stuck inside. Any suggestions?

[workingonit]

Need to know why you think your on/off gear inside the casing is stuck - dash light, vehicle grumbles or vibrates on hard ground? The unit is simple and robust if it is whats on an LT230 transfer case.

Have you tried lifting one rear wheel just off the ground, start engine and see if vehicle moves off? In theory if unlocked you will not move off and the lifted wheel will spin ie same thing happens off road on open diffs. If it is locked then in theory you should roll off the jack because your front wheels are getting some of the power, you still have traction.

[synthium]

It is locked as when I turn the wheels scuff and slide and the car vibrates. I am about to jack up one side (both wheels up) and try turning them back and forth to see if that disengages them

[workingonit]

If you hear or feel a clicking noise when moving your lock lever, and your lock lever holds its position in or out then the selector shaft is moving and the detante ball bearings are doing their thing. If this is the case it is possible the selector fork has come adrift of the shaft, or the tips of the fork have worn, or the tips are not (for some reason) not connected into the groove found on the actual locking gear.

RAVE manual, Haynes, internet search.

[workingonit]

Is your front locker off if you have one?

Try the one rear wheel off the ground thing first.

[synthium]

No front or back lockers. Will try rear first thanks.

[workingonit]

Clutching at straws, but if thrust washers in actual diff have 'fused' then maybe the diff is locked internally and not as a result of the on/off locker ring. Done any extended slippery driving without the diff lock engaged? Any unexpected noise before this current round of trouble?

[synthium]

Ok tried rear wheel up. Won't do a full rotation (handbrake off). I have the front and back drivers side wheels up now. They spin same direction in unison. Can do full rotations. Centre diff light still on.

[workingonit]

Regarding surgery - off with drive shaft, any wires, linkages and bolts. Pulls off with out too much trouble - just a pain. Oh, draining oil might be an idea. Just remember how it all assembles as you pull it apart. Watch for detente bearings incase they roll out - from my experience they should be reinserted from inside the casing before re-insertion of shaft - grub scrw and spring from the outside of the casing. The on/off ring and its fork should be obvious. Inspecting internals of the diff itself require splitting the two halves, and mark the two halves before you pull them as the bolt holes are not uniformly spaced from memory - you'll need torque wrench etc for reassembly.

[synthium]

Hi no unexpected noise but have had trouble disengaging in the past but usually after 20 mins of reversing and swerving it comes good

[Trundle]

Hi no unexpected noise but have had trouble disengaging in the past but usually after 20 mins of reversing and swerving it comes good

And you didn't suspect something at this point?

Or did you do the "I'll drive it till it really breaks" trick? I'm known for doing this...

[synthium]

Thanks for all the help but finally came good. 2 wheels in the air. Spinning the back while my mate changed the gear on and out of diff lock and finally it unlocked!

[synthium]

Sorry trundle what do you mean. How can I drive it until it breaks when it disengaged previously. As I said no unexpected noise. Thanks for the positive advice

[Trundle]

Just mean that if you've had an issue with it sticking and needing to reverse and swerve around for 20min to get it out several times before then there was an obvious issue, but you seem happy enough to re-engage the diff and continue to use it.
Nothing smart arse intended, as I am happy to drive some with a known problem sometimes, for any multitude of reasons, mearly a question, of are you going to look for the cause, or continue to drive it knowing it will likely happen again?
Be interested in knowing what was causing the sticking if you go down that path.
Cheers

[workingonit]

Good to hear you got it unlocked. Before your Iast post was going to suggest one more thing, and it may be worth trying pull (unscrew) the sensor out first in case it is hindering the change mechanism. I'm used to being under Disco so you may have a bit more room for reaching it in a Def. Reach up over the rear of the box and you will feel it by following its wire down, then figure out which ring spanner or open end will fit and unscrew.

Best if you take it apart and find the prob :)

[Iain_B]

I have had the centre diff fail to disengage before on a long trip out across the Savannah Way. At first it would take quite a few goes, reversing etc, until eventually it would not disengage at all. We were going to be driving on sealed roads for a while, so I had to get it unlocked. They way I got it unlocked (on the grass in front of the Cape Crawford hotel) was to jack up a front wheel to unload the transfer case and then pull and manually turn the lever. I had to do this everytime we got off the dirt roads, had to be careful as the exhaust pipe is very close. The diff lock lever would move across, and would move the lever but not in the right direction.

Turns out the linkage was bent, possibly from something hitting it, or since we started the trip shortly after the dealers had replaced the clutch under warranty, they might have bent it when re-installing the drivertrain.

It was an easy fix, just bent the linkage back again.

[workingonit]

Sounds good to me...and a unimog owner to boot :)

[synthium]

Once more thanks for all the help. And I will look into it further so I can actually use it without fear!