my 172 had a speedo driven gear box in with a circlip holding the diff in but the clip popped out, so I fitted a non speedo drive gearbox with a bolt in diff but my speedo doesn't work. I have rang Renault to try and get then to activate it on clip to send the speed from the abs sensor but they cant fit me in for 3 weeks. I have tried using a satnav and other gps speedos but there to slow cant keep up. what else can I do apart from sell the f**king car??