What are the major problem areas? Putting aside issues with 40+ year old cars in general, the main issues are rear suspension and cooling. In this regard, later cars are better than earlier cars.
The rear suspension works, and works very well. However, it requires much higher maintenance than a “regular” car. It’s an adapted design from a race car and requires similar maintenance. U-joints are subject to suspension loads and last a relatively short time, say less than 15k — later TC/S have larger joints which last longer. Check your u-joints for play every time you change the oil. Any play, replace them. Check the half shift shimming every oil change as well. Rear suspension rubbers fail, etc. Easily repaired if you keep a regular eye on things.
The Achilles heel is the rear wheel axle sourced from the 40 hp Sunbeam Imp. If you follow the service manual religiously, it is just ok. Skimp, and it will fail with the rear wheel making a bid for freedom. There are alternates but they are not cheap nor easy to fit.
The cooling system is marginal at best. Cool, humid climate and you’ll never notice a problem. First make sure the cooling system is clean and clear with fresh, mixed coolant. Next fit a better radiator fan. The early blades actually run backwards are ridiculously inefficient. You can get an aftermarket rad fan for an 1980s Mercedes that is very powerful and reasonably priced. Makes a huge difference.
