Thanks both. I was mainly referring to the aluminium (crush?) gasket that sits between the bolt together front and middle sections. In the end I couldn't get the middle and rear sections to part company under the car, so I cut the exhaust pipe just before the join to get the middle section out. I then tried removing the remaining middle section of pipe still inside the tail section but failed to get it out. I took the tail section off and a bunch of rusty bits dropped out of the end pipe. I then set to work separating the remaining bit middle section from the end section on my bench, but _still_ failed to get anywhere. This was after cutting with the grinder, twisting with mole grips, heating with a butane torch until glowing red, hammering a screwdriver between the two pieces until the tip of the screw driver bent. It's as if the two sections had been welded together, although there was no sign of this. Could it have been joined by heating the two sections to near melting and then hammering together? Are maybe the unit was sold as a single section (although I've not seen such things on sale anywhere I've looked)? There was no evidence of any assembly paste or similar anywhere near the join. No idea how it was done but it's made the job a real PITA.
Removing the end section made me realise (from all the bits dropping out) that the end section needed replacing so I have that on order now. It's turned a £100 job into a £200 job. I suppose this is often the way.
I find the issues I've had with this exhaust strange. The pipes and outside of the mufflers look fairly new with relatively little corrosion. But the problems seems to have all come from the flexijoint (which failed after about 12 months and <4000 miles) and the welds between the pipes and the middle box. Perhaps the short journeys we tend to do (with not enough time to heat everything up enough so the moisture boils away) haven't helped.
I was curious to know what the innards of the two sections were like, so I opened both up to have a look and have included the pics here for anyone else who might be interested. Middle box looks pretty ok inside - rusty but otherwise intact. It was packed with a woolly material (removed before photo) that I assumed was fibreglass of some sort. End box is another story - severely corroded and the perforated wall between the inlet and outlet has almost completely gone.
Also included the sawn off distorted inserted pipe that refused to budge in the slightest after much puffing and panting. A tortured thing it is indeed.
