I tried the Mr Clutch in Southend. They quoted a very good time on it (and price) but when I brought it in they said they couldnt do it because of supposed health and safety problems with my nitrous lines being in the engine bay. I showed them there wasnt even a nitrous bottle connected and they were just empty plastic lines but they didnt want to tackle it. I dont think mechanics that stupid should really be allowed near my clutch anyway!
There are basically two ways of doing a valver clutch. Remove the engine and box and split them on the bench, do the clutch change properly then put it all back. Or the bodge way which a lot of people do because it saves time and effort, which is AFAIK to crack them apart while still in the engine bay, slip the old clutch out, slip the new one in and hope for the best. Problem is the proper alignment tool that you need to do the job well wont fit in if you try the second method, so you could end up needing to do the whole job again fairly soon, and theres no way of knowing until it goes.
Bear in mind Im no transmission expert, this is just what Ive been told and it seems to make sense.
As far as the 172 goes, ask them if they do it in exactly the same way as Renault would do it - find out how many hours Renault quote and ask them if theirs will take the same amount of time and if its vastly less, ask them why. If youre happy with the way they will do it, and they can guarantee in writing that the clutch will sustain no premature damage using their fitting method then go for it.
