alright gaz i have had exactly the same problem on my 44.1 did you compress the spring when you first built it? I think this is what causes the problem... the way I got round it was to tighten up the slipper a tad bit more than normal then pack out behind the blue collar with o rings which meant when it started backing off it could only go so far. Not had them problem since. I will be there with the car tonight if you want to have a look
