The cause of my cambelt going slack twice has been diagnosed as a missing spring on the belt tensioner. When it got changed last the garage must have screwed it up. Anyway should be fixed tomorrow with a new belt, tough enough for the next 30,000 miles of hard graft!
I tell you only what the garage who is fixing it told me, he's been and ordered from Vauxhall whatever bit it is anyway. Lets put it this way, slack belt (very slack) twice in 7 months means something is wrong!
I'll know more when I pick it up tomorrow.
Also only needed one track control end for the MOT, how good is that, I'm made up at the minute so may celebrate in the pub shortly.
early XEs have a different pulley layout with a manual tensioner that doesn't self adjust - late ones have an auto-tensioner with a strong inbuilt spring - sounds like this spring was missing or faulty on Dans cars.
the tensioners are not interchangeable - you can only go from one to the other if you swap the whole pulley set and backplate.
i only used mine to help me "collect" the slack (winding engine backwards) before putting a bar in the square hole then nipped the pulley up, wound it round a few times checked the belt tesnsion and torqued (new bolts) it up then i removed the spring