My advice would be to buy yourself some motorcycle chain lube/wax. (Castrol or Halfords own)
Brilliant stuff for use on the leaf springs.

I use a 2 tonne trolley jack, with pads, on the axle and always use axle stands (and wooden blocks) before crawling underneath.
Other TMers will, I’m sure, suggest alternative jacking methods.


Bud
4/4 "Stanley"