Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Plus four has a ‘clonk’

Acquired my first Morgan 5 weeks ago, a blue Plus Four auto with wire wheels. It is a fantastic car and I love it.

But.

It has a clonk, it clonks when I change gear, either as a manual of in auto mode. It clonks when I brake. The clonk is definitely coming from the rear of the car, possibly from the area where the diff is.

Oakmere looked at it and said a diff mounting bolt was not as tight as it should be. After tightening the bolt it seemed ok but having driven it today the clonking is still there. It is clonking even when I drive quite gently so am very concerned about it and have decided not to drive the car until the issue is resolved.

Has anyone with a new Plus Four had any similar issues?

Thanks in advance.
Roger

Welcome to TM Roger.
In all honesty I don’t have any clonk. I do however have a ratttle from the engine somewhere under hard acceleration. Not too concerned but just aware when I’m pushing it above 4/5000 rpm particularly that it sounds a bit like a screw is a bit loose somewhere under the bonnet….
Hope your clonk gets sorted old chap
HB

Thanks HB, glad to be part of TM. No rattles in my car but the injector pump is quite audible which Oakmere said was normal.
Roger

Without wishing to state the obvious - you mention wire wheels - are they tight? Loose wire wheel on the splines would do the "clonk" exactly as you describe.

Hi Andymot. Yes I checked the wheel nuts and I presume Oakmere also checked them and they seem ok. How do Morgan owners tighten the wheel nuts? The hammer and spanner provided are ok but the manual recommends a torque of 110Nm so I have purchased a suitable socket (70mm) and will check the nuts with a torque wrench. Roger

Sorry to hear of your “clonk”, Roger - I must say I don’t have either or rattle — now. I did have a distinct rattle when I got the car and on investigating, my dealer found a small ratchet spanner lodged in the space under the spare wheel!! End of rattle!
My wife remarked that she was not sure it was a Morgan as it didn’t rattle like the three previous ones!!

Hope you get it sorted soon!

Roger,
Please add your location to your signature / profile

Given your car is from Oakmere in Cheshire, dare I assume that you may live in the area?
I'm in Preston, so if your nearby maybe we could "get our heads together" and see if I can assist

Suggest that before tightening the nuts, remove each wheel first and ensure that the splines and conical contact areas at the rear of the wheel hubs are generously greased. It works for me.

Morgan handbooks can be confusing. A toque value for knock on wire wheels is not normally given but one for conventional stud mounted wheels is. Are we sure that 110Nm is not just for conventional bolt on wheel lug nuts, I suspect it could be; please check.

If you are confident, jack up the rear (both wheels) pop underneath & get a mate to rotate the rear wheels too and fro & look for

Rotational 'slop' in the diff & propshaft, especially the UJ's
End float in the diff, push pull on each wheel
Check mounts at rear of gearbox nr output shaft

Good luck Roger and let use know if you find anything