Excitement in the household. I believe I have a rear differential "pinion seal" leak, where the rear driveshaft enters the rear locking differential. Only 24,950 miles on the beast.

@GavinC and my other Defender mates have self diagnosed and compared pics with their Deefers - none of them have any leaks so I don't think this is normal seepage.

Replacing the seal on one of these active torque vectoring diff's looks like a massively annoying job for a simple seal based on this video -- same repair on a FFRR with an diff that looks exactly the same to me --
Luckily I saw this before my warranty is up 1/1/25, in less than 2 weeks -- so just "eeking" this in on JLR's dime. Snagged an available appointment the day after Christmas at the local dealer.

(orientation of photos below: looking up from drivers side rear wheel area, laying on ground, at forward facing side of the rear differential, this is the locking diff)

Greasy. And there's grease on the exhaust. (and no where else under the vehicle).





More to come after the dealer appointment. May want to have a look at yours.

 

Interesting, I'll have to check mine to make sure it isn't leaking. I'll have to wait until the rain dries up before I take a look. My factory warranty is up on 1/23/25. Luckily I have an appointment on 1/6, and I'm having everything looked over and anything that needs to be replaced will be replaced.

 

Interesting that the prop shaft and/or its union to the ediff has evolved from MY21-22






a quick comparison of the suspected leaking MY21 on Nashvegas and my MY 22

both the same diff type.

 

Checked mine today. No visible leaks and my early 2021MY w/ a build date of 12/20 has the updated seal. I also have the rear locker.

 

@CincyRovers you mention updated seal. That would reflect the different prop shaft appearance from NashVegas' to mine and yours. Very interesting. I didn't read anything about that being a potential problem. Mine is MY22 with a build date in July or august 2021

 

Here’s another data point for nerds like me. My ‘22 D90 P300 with rear locking diff was ordered in late July 21, built 10/21/21, and delivered 12/17/21. Here’s what it looks like:

 

So my 2020 w/ locking rear diff looks different than at least 3 of yours (which means the part was revised!). aha !

 

That's the shiniest of the lot.

NSFW tag needed on these pr0p-shaft nerdery pictures. Very interesting to see the changes. I'd love to see some more examples of the earlier iteration.

 

The differential with the flange is only on all model year 2020 defenders. All 2021 and up were changed to the large nut orientation, locking or open. It was a production change. The change is also inside the differential. 2020 with the flange has the ring gear bolted to the carrier. 2021+ with the large nut has the ring gear welded to the carrier. It was for weight savings i e fuel economy. The front differential from start of production has a welded ring gear and the large pinion nut. Hence, if you see a large nut on your pinion vs a flange, the ring gear is welded to the carrier. So, if you have a 2020 defender with an open differential, it is much easier to install an air locker. Later production involves machining the ring gear off the carrier and drilling and tapping it. That is one big benefit to the 2020 open diff. Also replacing the pinion seal on the 2020 is much easier than the later ones. Special tools are required. The large 12 point lock nut is super tight! And both use a crush sleeve for pinion bearing preload, so you have to put the nut back exactly where it is and count the turns. Otherwise,you are replacing pinion bearings.

 

Thanks for sharing this info @sarek tremendously interesting.

I reckon there is no chance my local dealer would be able to do this without having to change bearings too. No chance.

On a side note I’m curious about the front diff. I have changed oil in rear diff and transfer case but do not see the front diff oil listed in the maintenance schedule. Is there an obvious reason for this I am too dumb to know? Can/should owners also change the front diff oil?