I know, I know..Just gets a little annoying . Annoyed with myself, I'm a proffesional engineer and meticulous with maintainance. It was'nt loose on the splines and just can't believe I missed it. Race a Yamaha MX bike which gets the nuts wrung out of it and it has not once let me down. To have a failure on the trailer is a first for me.
I was more hacked off there was no retention groove on the shaft. Normally this stops them coming off if they do come loose, you have to remove the bolt to get the lever off.
Ordered another one so apart from a wasted day and another financial drain all is well. Mind you I still find the "plastic" carb boot a right pain, is there no rubber in Andorra...
Just read "bikespace's" post and looks like good advice. Will make sure the new one is on there good and proper