Thomas, all the bush types (bronze or Nylon) are interference fits in the hub tube. So can be pushed out or further in to fit a lip seal. But if you push them in then they may not stay exactly in line and watch where the grease nipple is!
Not exclusively my idea - as many know a lip seal od 1.25 inch, id 1.0 inch by 3mm wide (excuse units) (around £2.00 GBP each) will fit in the end of the hub tube to keep dirt out. I fit with the lip pointing outwards to concentrate on keeping dirt out. NB The tube id is around 1.229 inch so too small for a 1.25 inch seal to push straight in. These seals need their od skimming slightly to fit. I push them onto a 1 inch rod and rotate them against a abrasive paper. Then tap them in.
Trust this helps - PJB.
