Hangar works #5 – Properly re-installing the rear mudguard

Since the first day that we got our Morgan 3-Wheeler, we could hear a low friction noise at the back. The car is new, and it has no soundproofing at all – as other 3-Wheelers owners know – and it’s completely open. So, hearing sounds, cracks and friction noises is nothing unusual.

But I found our noise unusual. As engineer and used to see big motors and rotating machines at work, I was concerned about it. And while turning sharp right with certain speed, the friction noise transformed into a loud vibration.

First suspect: the tire against something. But which “something”? My guess: the mudguard. Again, I asked my colleagues in the Talk Morgan forum and many replied immediately warning me about the rear mudguard’s factory installation. It seems they have the bad habit to install the screws and nuts inverted, with the long and sharp end of the screws looking to the inside of the mudguard, against the tire. And this implies they may touch the tire when the back-swing arm flexes.

Scheme of the rear mudguard.

I went down to the garage and asked my father to join me for help. We removed the boot inner tray to access the rear parts. First thing we see: the screws and nuts are effectively installed backwards.

The head of the screw to the outside? Wrong!

We have to remove the mudguard. And check for possible rubbing signs on the tire. Apparently, the tire is as new as it should be, considering that we’ve done few miles since we collected it from the dealer. But then, my father’s sharp eye detects a suspect black dust accumulated in the front screws of the mudguard plate.

Detail of the black dust on the screws. Happens to be rubber gratted from the tire!

We follow the obvious, which is checking where these screws are placed when the mudguard is fixed and… surprise! The left screw just matches a channel in the tire so no damage can be seen, just a few insignificant scratches, but the right one has been rubbing directly against the tire permanently, to the point that it has created its own channel. Hard to appreciate with the naked eye, as it is perfectly straight. But if you look closely at the photo, taken with good lighting, it can be clearly seen.

The rear mudguard is an extra, so not all 3-Wheeler have it mounted. But this is not an excuse! MMC should take seriously this kind of mistakes; and even more when we’re many who have complained about it!

However, the tire is not really damaged. The channel grated by the screw is less than 1mm deep, and thin. Nothing to be really concerned about. But, again, they should pay attention to these details!

We go for a short drive without the mudguard installed, and no friction sound at all. Still a little rattle turning right sharp, but you really need to turn very fast and briskly to provoke it. And it’s a totally different sound from the one we got. So, the improvement is tremendous. The rocket is much silent now!

Then we re-installed properly the rear mudguard and repeated the short drive. And still good. The permanent friction noise and loud vibration while turning right sharp have disappeared.

Another good father and son afternoon at the hangar!

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