Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) ‘Clonking’ brakes

Has anyone experienced a clonking noise from the rear of the car whilst gently decelerating or accelerating? This noise can also appear when gently applying brake pressure. The car has always done it but (and it might be my imagination) it now seems louder than previously.
We are currently touring in NW France where many rural villages have speed humps and traffic calming measures and maybe this is exaggerating the phenomena.
Just wanting to understand what it is and if there is any safety related concern.

Any advice or input welcome.

Hi

I did suffer "clonking" which I could notice at low speed gentle acceleration and sometimes deceleration. This was categorically down to loose spinners. I have a painted set of wire wheels and it turned out there was enough of height variance where the spinner sat on the painted hub that over time the spinner(s) would loosen off. Paint was ground back and spinners put back on with appropriate amount of thumping with mallet and spinner saver. Big thanks to the team at MWS who helped to solve the problem.

So if you have wire wheels you may want to give the spinners a few decent thumps, ideally with the wheel off the ground first and then back on the ground to finish off.

If you have wire wheels, hope that helps
Cheers
Neil

Edit - I forgot to note but when it first started my thought was that there was play in the calipers or some issue with the prop shaft.

I have experienced that effect.

Me too, on wires.
But, with early CX models on conventional wheels, I seem to recall that there was an issue with the wheel holes being slightly too big for the studs. Maybe someone else on here can confirm?

Yes there was the CX is designed for alloys unlike a trad that is designed for wires. So to fit wires there is an adaptor plate with splines bolted on where the alloy wheel would go.

I remember on early cars the holes in the plates were larger than the bolts so the plate could move.

Something will be wearing quickly so it needs sorting if it is related to torque transmission to wheels.

I called the factory as I wanted to be sure it wasn’t a safety related issue before I make the 500 mile homeward bound trip tomorrow.

Mark in customer services was very obliging and talked me through the issue. It relates to a lack of suitable grease (preferably graphite) on the splines of the output shaft and at the inner taper and the inner nut thread. The grease effectively acts as a damper and if there is inadequate grease it permits a very small amount of play which results in the aforementioned clonking. This is exacerbated with hot temperatures; hardly a problem in Normandy as the weather has been wet and cool!

I hope this information helps others. I will wait until I get home to resolve the issue but at least I know it is not a safety issue.

Great that you got an answer and peace of mind. Out of interest does that mean you have alloy rather than wire wheels? Safe trip home

No, wire wheels.

I Head the same problem. PlusFour MY2022 with wire wheels. Problem was solved by my dealer.