We had Enduro motor movers fitted 4 years ago to our single Bailey Discovery, at the end of last season the offside mover started to make a clicking sound under load, the company that fitted them have gone out of business, Purpleline have said the roller needs replacing, reading other posts is this likely after only 4 years?
I had one for nearly 6 years and the only problem was that chains gradually got noisier.I know some people had a pin on the sprockets come loose and this clicked each revolution as it rubbed on the casing.I doubt if it needs a complete roller it is normally the bearings that can be replaced.These fail as they fit ZZ bearings which are not water tight, if you replace then use RS (RUBBER SEAL)type.When i bought my new van last year i left it on the van as it was getting noisy, and as i always fit them myself i fitted a Powrtouch HD as it was cheaper to buy than the Enduro and had a variable speed control. Powrtouch also have a 5 year parts guarantee and made in Britain, unlike the Enduro.
I had similar knocking noises on one side with mine too, and as birdman suggested it was water that had managed to get into the bearings and rust them, I bought some and replaced with the RS type and all was fine, they are a fairly common size available at any bearing supplier and a cheap fix.
Dave
------------- Give a man a fish and he will eat for a day,
Teach a man to fish and you can get rid of him for a whole weekend.