Just had to replace the UJs on the rear prop. The prop was barely 18 months old and covered maybe 8000 miles in that time. The rear UJ had completely collapsed whilst the front had a slight bit of movement but as the prop was off I replaced it at the same time. The rear had collapsed to such an extent that I couldn't press the bits out and had to cut the UJ to bits with a cutting disc on the grinder before pressing out the remains and cleaning it up thoroughly. I've fitted Hardy Spicer HD UJs at £39 per pair so I'm hoping I get more than 18 months out of them! The UJ fitted thread on here came in handy I can actually go above 35mph now and still see things in the mirror It's still smooth at over 50mph

How long do UJs normally last? I thought I'd asked this question before

How long is a piece of string? Depends on heavy use, light use, wading, abuse etc, climb under and grease them monthly for longer life.

Depends what use you give them,road only and regular grease several years.
The worst thing is that watery mud that has fine silt in it,been through that then grease as soon as you can. Quality items do help.

Having a lift kit put more stain on them

Hardy Spicer don't make UJ's any more , they haven't done for quite some time.
Hardy Spicer props and UJ's are made in India by Hindustan Hardy Spicer Ltd under licence to GKN, their quality is questionable to say the least, not sure about the Japanese NTN uj's.
There are better quality UJ's and props out there than GKN.