I just installed a 4" lift on my FJ40, so far no universal joint problems. My mechanic swears up and down that I will have some. I have been greasing the shiznit out of the joints, basically pumping through new grease until all the old is out, and then wiping away excess.  
o you yall think pulling a 400lb atv on a 500lb utility trailer for about 2.5 hours at 65 mph twice in one day is asking for universal joint failure? ???