Help with source of oil leak

My Discovery 2 has a minor oil leak from the plate just to the front of the rear axle, as shown in the photograph:

This is after I'd cleaned up the area and the car has been stood for a day. The oil can be seen forming a drip at the top left hand corner of the plate. The leak appears to be coming from under this plate. Firstly, what is this plate, and secondly, is it feasible for there to be a source of oil leakage from underneath it?
Now, my car recently had an advisory on its MOT that there was a 'not excessive' oil leak from the rear diff'. I had a garage have a look at it and paid them to replace the rear diff oil seal plus top up the diff' oil, which they said was the source of the leak.
When I cleaned up the oil from around that plate I also wondered whether the oil was leaking from what I believe is the diff' oil seal. This is in the photograph below. Although there still appears to be some wetness, it is not trickling down onto the plate and so it is not the source of the oil leak.
Can anyone advise please?
Thanks, as always.

Looks to me like the pinion oil seal is leaking.
(The differential oil seal is the one that goes between the two halves of the diff.)
As the pinion turns constantly as the car is driven, inevitably it will eventually wear the seal that keeps the oil from leaking out from the diff to the front of the diff where the pinion drive enters it.
The garage ought to have spotted that and done it. It is a bit more difficult to do than the other one
Maybe you actually had both leaking, but the difference between the two leaks is pretty obvious.

Thanks,
So will it leak out beneath that plate?
Andrew

Without crawling under my own Disco I'd say yes.
There are 5 ways diff oil can come out of a diff, apart from via the side tubes/the half shafts and hub seals, and these are:
Filling plug.
Drain plug
Diff seal
pinion seal
Breather
So I'd say the oil has got past the pinion seal and dripped down onto the plate.
Maybe others have another idea, I confess I have only taken a Disco 1 diff apart, (although I have worked on many diffs), but I don't think there is much difference.

Thank you very much. Andrew

Stanleysteamer said:

Looks to me like the pinion oil seal is leaking.
(The differential oil seal is the one that goes between the two halves of the diff.)
As the pinion turns constantly as the car is driven, inevitably it will eventually wear the seal that keeps the oil from leaking out from the diff to the front of the diff where the pinion drive enters it.
The garage ought to have spotted that and done it. It is a bit more difficult to do than the other one
Maybe you actually had both leaking, but the difference between the two leaks is pretty obvious.

Click to expand...

++

Worth making sure your axle breather pipes are clear too -otherwise a build up in pressure can cause leaks.
Griff

Stanleysteamer said:

Without crawling under my own Disco I'd say yes.
There are 5 ways diff oil can come out of a diff, apart from via the side tubes/the half shafts and hub seals, and these are:
Filling plug.
Drain plug
Diff seal
pinion seal
Breather
So I'd say the oil has got past the pinion seal and dripped down onto the plate.
Maybe others have another idea, I confess I have only taken a Disco 1 diff apart, (although I have worked on many diffs), but I don't think there is much difference.

Click to expand...

What he said.... My money is on the pinion seal...

https://www.johncraddockltd.co.uk/f...nd-2-freelander-1997-on-rrc-1992-onwards.html

Thanks for all this advice, and the video. I've not done the job yet as I've just moved house.
Would someone please advise on the non-standard tools needed, particularly on the part needed to remove the centralising peg from the pinion flange?
I don't recall the man in the video covering this subject, but will a certain size of slide hammer do, or is it best to get a special tool - LRT - 51 - 009?
The film is a bit too sales heavy, but I found this:
https://fourby.co.uk/puller
Thanks,
Andrew

ANR said:

Thanks for all this advice, and the video. I've not done the job yet as I've just moved house.
Would someone please advise on the non-standard tools needed, particularly on the part needed to remove the centralising peg from the pinion flange?
I don't recall the man in the video covering this subject, but will a certain size of slide hammer do, or is it best to get a special tool - LRT - 51 - 009?
The film is a bit too sales heavy, but I found this:
https://fourby.co.uk/puller
Thanks,
Andrew

Click to expand...

That tools is a reasonable price.
I made one up using a bit of threaded bar, some plates/ big washers and a length of wide tube made from an old box spanner. Before that I tried a slide hammer, that didn't work.
Do give it a thorough soaking in the freeing off liquid of your choice over a period of days before doing the job.
and when you have the peg out do check the tightness of the pinion securing nut. On my D1 mine had come loose. (Whole reason for taking it all apart.)

Checking the rear axle breather pipe to see if it was blocked, I can't see how it is fixed to the axle. Can someone advise please? I didn't want to snap anything off.
I blowed and sucked on it but there didn't seem to be any movement, so I'm looking to disconnect it.
Also, it went to a connector above the rear of the nhs wheel arch and from this connector it continued from view above the rear bumper/boot space and I couldn't locate the end. I gently tugged on the section that went above the bumper but there was no give in it. If this hasn't been freed since its factory setting, will the ultimate outlet of this pipe have been fixed somewhere above the rear bumper? Or will it be loose and just need pulling out?
Thanks,
Andrew

It is a bit embarrassing, as it seems simple DIY, but can someone tell me how (if it's possible) the breather pipes (disco 2) can be uncoupled from the connector shown in the attached photograph?
I've spent ages trying, in vain. But the thing is I recall having had it apart before. The green caps come off with prizing, but the pipes are secured inside more plastic.
I've still not cured the leak from the rear axle and wanted to try and determine whether the breather pipes are clear.
It has been to a good LR specialist garage twice, had the pinion seal replaced and the flange seat replaced, but still the leak. The garage say that their mechanics checked the breather pipe was clear, but I want to check for myself. I can't take it back to the garage, because I now live 450 miles away.
I'm at a loss to know what else to try. The leak only comes on when the car is running; not when stood, engine off. For example. I moved the car off and onto the drive to reverse onto a trailer and quite a large spill of oil came out afterwards but the car had been stood for two weeks before this with no leaking oil.
I'm keeping the oil topped up.
Thanks,

I had the same leak from pinion two years ago, I tried blue devil transmission sealer, it has worked for me two years although it is not recommended by someone.

ANR said:

I've still not cured the leak from the rear axle and wanted to try and determine whether the breather pipes are clear.View attachment 247914

Click to expand...

When I had an oil leak at the wheel hub on the rear axle, I too was in a bit of a dilemma on how to check the breather pipe without disconnecting it from the axle. The quickest way which worked for me was to blow air into the diff from the filler hole until I got a free flow of air through the pipe. I used a low pressure pump, similar to the one used to inflate air mattresses and no more leaks !

Brilliant, thanks! I'll give that a go.
Andrew

ANR said:

but can someone tell me how (if it's possible) the breather pipes (disco 2) can be uncoupled from the connector shown in the attached photograph?

Click to expand...

You simply push the green caps in towards the centre of the connector whilst pulling the pipes out.

Thanks.
The breather pipe is clear through both sections, but the leak is still there. At least I know it is not that. I'll try the leak sealant.
Andrew