Hi Geoff, If that is the encapsulated Rubber/Torsion Bar type axle design they used the Elko brand I think on all the Original Phoenix Off Road Caravans which had ATM's up to 3.5 tonne. I never heard of any problems but they shut the doors back around 2006-2007. The newer Phoenix now owned by another manufacturer use different Independent Suspension set ups. My first experience with the Alko Rubber/Torsion Bar type was with an 1986 model Jayco camper trailer about 3 yrs old ,it seemed to handle the rough roads ok. But I have seen instances of the Rubber bushings showing fatigue causing excessive camber wear and on some badly overloaded car trailers seen the main lever/stub Assy's snap off. These were small weight carrying axles though Not like the Large H/Duty Axles that the Original Phoenix's were using. As long as they are Rated for the Correct ATM's with the higher allowance for bad conditions I could not see there being any problems. They would be better if Shocks could also be fitted but the design sometimes doesn't allow, just like the Simplicity designed suspensions. Cheers Kev.