My daily treatment of the clamp had had no effect whatsoever and when I had used all the force I dared on my spanner I decided to avoid various potential injuries and accidents by cutting through the centre of the clamp's single bolt with the trusty grinder equipped with a 1mm disc. 15 seconds later I used the clamp pliers to open the clamp and slide it up the centre pipe. Both rubbers slipped straight off the mounting pegs thanks to their liberal coating of WD40 over the last few days and the old back box was on the floor. I cleaned up the end of the pipe, moved the mounting rubbers onto the new back box and set about dry fitting it. This is where things started going awry because the new clamp I had been sent simply wasn't quite big enough to go round the bell end of the new box satisfactorily. I went under the car and checked it on the pipe and it was just a tad too tight to slot around. I think it may have gone on with the aid of a significantly heavy persuader but that is not my way. So I took it to the bench vice and opened it out about 3mm. Refitting to the pipe was fine but with the welded bolts splayed that bit more the other half of the clamp would not fit over the bolts.
At this point I concluded that the clamp was fractionally small in diameter as well as rather too "Veed" in profile to make a decent joint. I grabbed the clamp and considered the situation. Car half in the garage, SWMBO's car out on the street, backbox hanging on car but 3mm away from the pipe. Could I wrap it in exhaust bandage in order to get it out to clear the garage and then order another clamp for another day? Problem would be having to clear up etc. and then set it all up again another day. So I called our local motor factor to discover they were offering a click and collect service. Did they have my clamp? Not as such but they did have a range of clamps and I could take mine down for them to match up + a bit. On arrival they only had one clamp close to the right size and it was 1-2mm larger. I noticed it also had free bolts where my clamps were welded to on side so I could fit longer bolts from stock if it was too tight and clamp it into position. So I shelled out the necessary £3.28 and headed back.
I decided to fit longer bolts anyway as they were 60mm M8's and I hold 100mm M8's in stock and fitting them would make the whole install much easier. So I dug out two new bolts, applied the sealing paste to the bell end of the pipe and then pushed the joint together, dropped the expanded but already double bolted clamp over the joint. and did up both nuts evenly over locking and flat washers. Once I was happy with a perfectly square and oozing all round joint I nipped them up and then added a locking nut to each bolt. Finally I cut off the excess bolts with the grinder leaving a proper job and declare it as job done.
It certainly looks much better now and I am happy that will outlast my ownership of the car.
And there was no doubt it was seriously in need of it: