G reg 90 with disc brakes on rear axle.

Rear hub seal was leaking on one side, so I replaced seals, bearings, discs and pads on both sides.

200 miles in and its still leaking, all over my discs. quite sludgy (assume from oil mixing with pad dust?).

When I stripped down, I found my thrust washer was FRC8227 (not seen one of them before), but unlike the parts diagram, the half shaft does not stick through the 'driving member' and have a circlip, it has a closed splined hub cover. The stub axles were not pitted and all looked ok. Previous owner added an extra seal, so there was a seal both sides of the hub, so maybe there have been problems for a while?

It is the same side that is leaking again, so its either a coincidence and I've nicked the seal? Or something else going on here?
I am also unsure if there are any differences / issues given the make up of the hub? Can I interchange all these parts without issue?

G reg would have been a drum rear brake set up with single seal in the hub.
Your rear axle may have come from a later 90 or more likely a Disco.
Check the axle breather is clear, hole in the banjo on the axle can block.
Different era hub's and stubs do not mix.

Yeh its a axle from slightly later defender i think. Breather is fine, checked it so many times just in case haha.

Anybody got an idea what could be causing the leak to continue?

Looking at parts;

From VIN LA930456 axles, Stub axle FTC3188 which corresponds with FTC942 hub and has thin 'washer'. This has the drive shaft attached to the hub cover.

The only set up I can see with the FRC8227 'spacer' is that of V8? Upto VIN 930455. But this set up has the drive shaft secured with circlip. There is a different hub and stub axle number in this set up.

Is there any way to identify what stub axle and what hub I have to confirm if I should be using this 'spacer' rather than the washer?

The fact the leak is sludgy means the axle oil is leaking into the hub mixing with the grease then getting past the seal, have you checked to see if there is a seal inside the stub axle?

The seal is a grease seal and not an oil seal, hence the leak.

The seal land could also be worn, speedi sleeve will sort that out.