Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Roadster 3.7 V6 CATS

Discovered recently whilst cleaning underside (I know ) severe corrosion on CAT assemblies both sides although top pic of offside is worst.





The CAT's themselves plus associated pipes appear to be stainless with no issues but there are short pieces of flex welded inbetween CAT and silencer coupling. As can be seen these have nasty cheap mild steel originally plated collars each end to interface and hold the protective braiding. Whilst wiping rag over, large pieces of solid rust fell off from what was the collar over half the circumference. You can still see the weld is intact with no signs of blowing yet! Unfamilar with construction I guess the actual flex tubing together with braiding collars are collectively welded onto stainless to silencer coupling pipe and similar at the CAT. Mixing stainless and mild steel in a weld clearly not to be recommended either.

Seems unlikely I'm the only one suffering this on my six year old 31,000 mile car given the nearside one is not far behind, so wondered if anyone else has noticed similar and what action they took? Is it possible to have entirely fresh flex parts welded in for example and to the degree of accuracy required?

You're right Richard the flexi couplings are probably a lower grade of stainless or just mild steel as stainless suffers with stress fractures quite quickly as it is harder than mild steel.
The braided stainless covering acts as a debris shield, a heat dissipater and aids in fast evaporation of water. In my experience yours although looking bad, ie not perfect, is (something we all strive for in our Morgan's) probably more structurally sound than you think. The flanges are really where the braided covers are fitted and if an end fails and the braid starts to roll back just fix it with a stainless jubilee clip or the like. It might seem drastic but tap away the rusted areas and wire brush to sound metal as rust acts as a sponge and anything you remove has no structural integrity so will not weaken the joint. Worst scenario, if you eventually have a failure there are many bespoke stainless exhaust fitting co's around who would refabricate new flexi couplings in for you, you could also request that they be removeable for replacement! Think car builder stock exhaust parts too.

Thanks for reply and assurance sewin