Flange, seal or cap?

Well the rear wheel is off again on my 1987 Landy 90 and the usual cleaning off the residual diff oil from around the inner wheel. Leaking out of the end cap, again (not past the seals and on to the brake shoes which is fortunate). Breather is clear, so I am now wondering, could it be the flange I need to replace so there is less movement on the splines or the crummy cap that does not seal the end of the half shaft. I see there are heavy duty options with screw on caps, but would rather not spend £80 ish. In know this is a frequent question but there does seem some ambiguity on people's thought, so I would like to hear any suggestions to cure this irritating problem.
Once I have this sorted, I can get back to looking at plating the front outrigger...don't you just love 90s.

I have found that today's replacement caps are a bit rubbish, some sealer can help.
However on my 90 I now use series steel cap's. Tougher and can be reused if knocked off. [ if found ] Seal with a touch of silicon. Cheap fix if you don't mind the old look.

I had wondered about the metal caps. Do they fit? I think with my spacers and Disco alloys then they should have the space. I did put sealant on the previous 2 plastic ones and it leaked through. If I move the wheel slightly you can see the oil weep past the splines. It appears these can wear and cause a bit of take up in the drive train, which there is in mine. Having said that, there are a hundred different things that could be causing this.

The drive member splines can wear. Your Landy's hubs are lubricated by the axle oil unlike later models that use grease. Steel caps is what I have on my 1990 90. Later models have smaller end's on the drive flange so do not know if steels would work on them. Check axle breather is clear.

The last set of plastic caps I bought are so tight I have to tap them on with a mallet = no leaks. They came in a blue bag. With the older rubber sets I used plenty of heavy grease which worked well to keep the seal intact.

The caps on mine leaked, I just re-fitted them with sealer.

I think I may go the series metal cap route. I fixed them with hylosil last time and still leaked after a while. Still, the welding around the rear damper mount and bump stop needs doing first, then the front outrigger repair. Oh joy!!! Lol