I'm currently replacing my auxillary drive belt and tensioner on my 172 sport with air con. This is NOT the cup model. I've bought all parts from Renault dealers and have all the diagrams and pictures of the engine and which way the belt is fitted. No matter how hard i try i am unable to install the belt. I've tried adjusting the large tensioner but to no success. Is there a special tool(s) required to do this? I can't get enough slack on the belt to enable it to go over all the pulleys. I'm definetly putting it the correct way on the pulleys.