Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Morgan Plus 4 - Drive train noise

I have the same noise on my 2008 +4 (and it was the same on the other car of the same age I used to own) and I am advised by a dealer I trust that it's totally normal for the reasons given above. It's disconcerting and I have been under many none Morgan's whilst they are running when up on ramps and never heard anything so loud. However as you report the noise is only there when stationary (much worse when parked in my garage as the noise reflects back of course) there are no stiff changes or gearbox issues at all. I have heard it on new cars and cars with 30K miles on the clock and it seems the same so I am sleeping easy on it.

My advice would be to keep a note of the exchanges between you and your dealer (emails and their replies) then you have proof that you raised the concern during the warranty period should things get worse later on but I think/hope you will find they will stay as they are.

I have the same problem as reported by the OP on my 07 +4 with 14K miles. I can also here the noise in first gear. IMHO its a bearing or bearings in the box. I doubt if an additive will make a long term difference.
If you look around other forums you find the MT75 gearbox a bit of an unloved beast with noise issues but some boxes obviously go on for years in this state.

As to what oil it should be? There are two opinions, a special ATF type oil or a 75W90, it does seem to depend on the age of the box. I have not decided yet what to use when I change the oil but I shall probably drain the old oil and see which I think it is.
Cheers
John

Thank you all for your responses.

Just to clarify, as I may not have explained this issue correctly in the first post: the noise is only present when the clutch pedal is up (pedal not depressed = clutch engaged); it is most apparent in neutral at a standstill and at tickover; it may still be there when moving but it is hard to tell amongst all the other noises.

I intend to take CBY's advice today and see if the noise smooths out/reduces when I increase the revs in neutral with the clutch pedal out. If it does then it may just be mechanical rattles that may benefit from checking the correct gearbox oil has been used (as per Morgan/Ford recommendations) - or indeed an additive as suggested by the dealer. I will report back my findings on the rev test.

Just checked the car as outlined above.
Mechanical noise is a whirr not a rattle.
Increasing engine revs increases the frequency of the whirr until at about 2.5k revs it is just a high pitched whine - less audible as a noise though because it has been overtaken by the noise of the engine.
The gear oil was changed by the dealer during a service carried out on behalf of the last owner in April 15 - though the invoice just says: LGEAROIL Gear Oil Qty 5 (I assume litres). I will now see if the dealer can advise me on what oil was used. The car has covered 2k miles since the service.

Mine has been noisy and baulky since new.
Done 18000 miles less baulky and still noisy.
This gearbox used on 4wd Ford Cosworths so plenty strong enough.

Firstly when was the gearbox oil last changed?

I would just get the gearbox oil changed first - see if anything changes.

If you want to change the oil, you can go by a Ford garage, they know your gearbox and have the right guenine oil. This is surely not very expensive.

At idle, go out of the car (brake on) at 4 feet away and hear. The noise is perhaps different. When you are in your Morgan you are very close to the gearbox, you seat on your car and you hear by 2 ways: your external ear, but also you inner ear which traps the frequency by mechanical transmission.

On a motorcycle you don't have the same sound if you stand up.

Make a test: take a long screwdriver, touch the shift lever and apply your ear on the handle. Horrific... but normal. You can try to do it on the cam cover. Don't be affraid. What you hear in mainly through your inner ear. It is used by mechanics to determine the noise source.

In the first company where I worked in 70-80, we made gears for ships, with more than 2.5m diameter wheel. For noise analysis we used Brüel & Kjaer analyser.

Thanks for the responses and advice.

As I mentioned earlier the Gearbox oil was changed in April this year; I have emailed the dealer who serviced it to ask what oil was put in. If it is anything other than that which is recommended I agree the first thing to do is change the oil to the recommended one. I would then see if that made a difference. I have also asked what the additive is that the dealer is proposing to put in......I will let you know the answer when I have it (hopefully not sawdust!!).

I have always been cautious with additives, they range from useless and ineffective to positively harmful.

incorrect oil types can be dodgy too.. an EP Hypoid in my Velo box will eat the bronze leaving the oil like golden syrup..

I'd check what they are going to use before they do anything..

The gearboxes on both my 4/4 and my Roadster both exhibit whirring noises when in neutral with clutch disengaged....as have a number of my BMW motorcycles...all from new or from relatively new. I was told some years ago that it was the idler gear and nothing to be concerned about......so it's never bothered me!