[sunset06]

Thanks Focmachine, I suspect it was your post that highlighted to me that the tensioner (T-43115) in my Gates TCK294B isn't the correct one. All the online parts search sites give like 20-30 compatible tensioners. Then I look up the detail for each, and they either specifically say:
- do no suit ST170, or
- they say they do, but that they also suit 10 other Ford/Mazda engines (988M-6K254-AE). It's really frustrating.

However, phoning Ford service information (from Ford via parts in Melbourne) the proper part is 2M5V-6K254-AA (and not 988M-6K254-AE=normal Focus). I assume that part is what is on my ST170 Focus which I've owned almost since new and has done 160,000 km without trouble and without a cam or auxiliary belt change, so keen to know why you are concerned that the Ford specified one is dangerous ?
ps. Matt was very helpful, but they stick to later model Foci. He tried to work out the original manufacturer, but wasn't successful.