axle oil leak

Hi, I have a 110 300tdi. I have recently had a few drips of oil on to the rear offside rear tyre, today I removed the wheel and found the oil was coming from the rubber cap on the end of the axle. Is this anything I need to be too concerned about ? When I removed the cap I noticed that the half shaft had some welding on the end which I presume isn't original - I remember reading sommat on ere welding half shafts or flange plates I think, I'm no expert, was just wondering if if is a good or bad thing ??
Also I have an EGR system fitted, if i just disconnect the EGR control box thing which sits by the battery will it stop the dreaded EGR from functioning. Thanks for any help !

You can weld the half shafts to the drive members, I have welded shafts on my 110 and it is common here in South Africa as there is then one less place to have play in the transmission and you save on replacement items.

BUT the welding must be done with a TIG (not MIG or stick) welder, and only on the outside of the drive member. If you weld the inside it will break the half shaft there. The shaft and the drive member are made out of different steels. Weld on the axle to get the alignment right.

I had mine welded because the half shaft would come out and push the hub cap off, letting oil out all over the wheel. The circlip keeps the shaft from going IN, but not OUT.

Thanks for the explanation, I bought my defender fully reburbished from a specialist dealer so I presume the welding was carried out correctly as a precaution perhaps.

Its a bit strange. If the shafts are welded there is no need for the plastic cap, but maybe it is just a tack weld to stop the shaft coming out as mine did.