Defender 90 300tdi difflock not doing anything

Hi, recently got a defender but the centre difflock does nothing, when I push the lever across it moves freely with no feel of anything happening and it definitely doesn’t engage. Wondering if the linkage has dropped off or something but not sure the best way to have a look as don’t really know what I’m looking for and where it should be. Any help appreciated.

Search for a manual, or put it in diff lock and jack up 1 wheel, can you turn it?

J

You could try watching the helpful video in the link, also does many more helpful videos.

Don’t just psh it across, pull it back or push forward to engage high or low

Ollie_Mif said:

it definitely doesn’t engage.

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How have you determined this? There are ways to check, just wondering how you got to this conclusion.

Moving the lever over does not in itself put the center diff lock in.
What it does is allow the mechanism in the transfer box to go into lock when it wants to. [ when parts line up inside] Lock lamp on dash should come on at this point.
Much the same when coming out of lock

300bhp/ton said:

How have you determined this? There are ways to check, just wondering how you got to this conclusion.

Click to expand...

Driving up a Steep incline the front wheels spin only, try to reverse up the back wheels spin.

Light doesn’t come on, lever moves freely side to side with no mechanical feel

the in car linkage goes to the transfer case in line with the two props

so if you crawl underneath you will see the linkage and maybe just a tap with the no 1 Land Rover tool

Ollie_Mif said:

Light doesn’t come on, lever moves freely side to side with no mechanical feel

Click to expand...

Thanks.

So, the lever should be pretty easy to move sideways, but more resistance to change from High to Low. There isn't a definitive click or feel from the lever for diff lock.

You may also need to drive forward a little way to get it to engage, it may not do so stationary. I'd also be tempted to try it in low as well as high.

If it hasn't been used for a long time, then it might not want to engage at first.

Also worth noting the light may not be working, either down to the bulb, the switch or a broken connection.

With diff lock out, jack up one wheel (front) off the ground, doesn't need to be high, just enough that is isn't touching. You should be able to rotate the wheel freely, you'll be able to see the front prop rotating. Put it in diff lock and the wheel will no longer rotate (it'll still move, but not freely rotate).

If it really isn't engaging you'll need to check the linkage on the transfer box, you should be able to manually move the linkage from under the vehicle.

Ollie_Mif said:

Driving up a Steep incline the front wheels spin only, try to reverse up the back wheels spin.

Click to expand...

A better way (more scientific like) is to unweight a wheel on each axle (or just 1 if that's easier) and try and spin that wheel by hand.
Make sure the main gearbox is in neutral and the handbrake is not on.
Chock the wheels on the ground.
If the transfer box diff is locked, the wheel won't turn, if it's unlocked it will (it turns the propshaft too).
If you have 2 wheels off the ground when the lock is on, turning 1 wheel by hand will spin the other too.

Get someone to lean into the cab and while you rock the wheel back and fore by about 1/2 a turn, get them to turn the difflock on (push it away from the driver) - hold it for 20 secs or so and then off again (pulling it back to the driver).

Have you watched the video?

Ollie_Mif said:

Light doesn’t come on, lever moves freely side to side with no mechanical feel

Click to expand...

I dont feel much if any resistance when I move the stick either, but then mine works.

Stop with the videos and do some testing as has been mentioned.
Get underneath at check the linkage is still connected. Jack up a wheel.

We can only help, if you help us.

J

Thanks a lot for the help and suggestions, will jack it up and test it later today, where should I be looking for the linkage exactly?

Here is a link with some good pics of the offending thingy

Before crawling under. I’d seriously just try driving it on a suitable surface with it engaged. It might just take a few car lengths to slip in of it hasn’t been used for years. Then jack up one wheel and check if it is or isn’t working.

With @marjon here, OP needs to see if linkage is connected and moving.
He has already done a good test on suitable surface noted in post above the result of which shows no lock engaging.

tottot said:

With @marjon here, OP needs to see if linkage is connected and moving.
He has already done a good test on suitable surface noted in post above the result of which shows no lock engaging.

Click to expand...

Maybe I miss read it. But all I can see is a stationary vehicle with them moving the lever left and right. Unless you are off road, it can be difficult to tell if it is working or not. Hence jacking up a wheel.

By "post above" I mean one further up when he notes testing on a sloping slippery surface.

weather's been awful so havent had a chance to jack it up but it came from the family farm and im pretty certain the lock hasnt been used for a fairly long time so may try driving around whilst trying to engage it then testing it. i've got a decent idea of where this linkage should be from the forum linked, looks to me like it is on the driver's side of the gearbox just behind where the front propshaft flange is?