Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Chassis Cracks- Lower Front Wishbone Mount

I have read much on this subject and will repeat what I have said on private mails to other owners with cracks in this area.

I do not feel that the problem is poor design or poor welding but the lack of post welding heat treatment. Welding cold metal causes problems in the heat affected zone adjacent to the weld. Welding a tube on two sides causes great stress in the area around the weld. A welded repair may well suffer the same fate as the original. I have repaired my own crack and have subsequently treated the tubes on the inside with linseed oil in the same way that aircraft fuselage space frames are treated. A full description of my work will appear on my website as soon as I have time to write it all up.

My conclusions are best guess based on long and hard won experience. What we need here is a qualified metallurgist to study the situation and write up a report. Do we have one on the list of forum members?

The chassis tubes, by the way, are electric resistance welded tubes of mild steel, not seamless drawn tube which might have been better but would still not be immune from the same stress issues.