I finally bought a Morgan 3 wheeler after years of wanting one. The car is a 2012 version, fitted with a new chassis and many upgrades and has about 12.000 kilometers on the odometer. However, the first weeks of ownership have not been trouble free so I have been tinkering around with it a lot. This was expected and I don't mind it, but now I've run into an issue that I can't seem to wrap my head around. I have this weard clunk coming from the back of the car. It's most audible on the right side of the car.
When the car is cold, everything seems to be perfect. I can perfectly drive it without the noise appearing. After about 30 km however the noise slowly starts to appear. It's faint at first, but it gets louder the more you drive it. I can only hear it at slow speeds, but if you keep driving it the noise even becomes audible at speeds over 60km/h which is worrying to say the least. The noise is speed-related in frequency, but not in loudness. The noise appears with the engine off or on, in gear or not in gear, .... so I don't think it's related to the engine, clutch or gearbox.
In this video I start rolling down a bridge with the engine off and the car in neutral: It's clearly there and pretty loud + the intensity increases as the speed increases. After making this video I let the car cool down and the cracking had again gone away until the next time it's warmed up.
I don't think this is a unique example. You can hear it in this video as well and that is a completely different car. When I slow down at 9 min 16 sec, you can hear the faint sound coming from the rear as well: That's a friends car and I didn't notice it at the time, but when I hear it now it seems to be the exact same thing.
I suspect it's the rear bearings, but maybe someone else has experience in this field?