Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Bevel Box Service Reduced Noise

Just an update.....

I never did get around to draining the "Excess" oil from my BB.

It did drip about three tablespoons on my garage floor overnight after the first hard run through the hills, other than that no other loss.

The BB is still very quiet at all speeds and loads.

Perhaps the main issue with the BB's noise and failures has to do with a lack of oil. There have been a few posts of owners who have found no oil at all, or possible so little oil that it would not drain out.

This may be an area for new owners to double check after taking delivery, even after the "extensive" PDI done by the dealer.

I'd be interested to hear from anyone adventurous enough to try the extra amount of oil to see if their results would be the same.

My bevel box had oil and never had a leak. Our failure came without warning and was an instant lockup of the rear wheel while at highway speed. The only reason there was not a serious consequence was that it was on a straight road with no other traffic around. My confidence in the safety of this little machine has been shaken and I wonder about going forward.

The idea that new owners do their own double check following taking delivery is sending a massage to the manufacturer that somehow their quality control and manufacturing processes are acceptable. Is this the rationale you use when buying a new $50,000 car? Check it out to see if it is safe?

On the contrary, this is Morgan's responsibility to deliver a safe product. We could have been killed by this failure.

Just think. Moto Guzzi have been making bevel drives for nearly 50 years and, with care they will typically last 100,000 miles. The latest version is driving a bike that produces 96 hp and weighs 337 kg. True this is a little less than an M3W but in the past Guzzi final drives have driven sidecars and a good number of 3 wheelers from various manufacturers. The only catastrophic failures that I have ever heard of resulted from gross abuse on the part of the rider and that resulted in cracked casings not bearing or gear seizures.

Plenty of other manufacturers also use bevel drives; BMW, Honda, etc. etc.

Clearly there is nothing wrong with the concept so there must either be a problem with the design or the quality of the components, or both. I would imagine that Morgan rely on Quaife to get this right and I am sure they are giving Quaife a very hard time. Why a company that is renowned for manufacturing gearboxes and transmissions can't get this right is beyond me.

I agree. When i was at the factory some time last year they were talking about doing a noise test on all the bevel boxes by powering them up under some kind of load to decide which ones would be acceptable with regard to noise level, before mounting them in the cars. I do not imagine this was ever put in place and if it was, the question then is:- "acceptable to who?".
Who sets the standard?
In my opinion the only acceptable bevel box is one you can't hear.

Rgds
Keith

bevel box was my first lubricate with black grease that contained molybdenum certainly after replacement due to leakage seal my second bevel box was delivered dry and filled with 75/140w synthesis, since it is much quieter.

[quote=GreyGoose]My bevel box had oil and never had a leak. Our failure came without warning and was an instant lockup of the rear wheel while at highway speed. The only reason there was not a serious consequence was that it was on a straight road with no other traffic around.



Grey Goose,

Sorry to hear of such a dangerous failure!

Have you found out why it failed?

There's no way for an owner to check a component like the BB to prevent that type of mechanical failure. Short of diligent routine maintenance and a cursory check before each ride (as everyone should do with a motorcycle) there would be no way to foresee a major component failure. And I agree, there should not be these types of issues with a $50k vehicle.

I am most interested to see what went wrong with your box, seized bearing, broken tooth etc.

I've drained and refilled my BB oil this week.

I went out for a drive to get it warmed up before stripping out the seat and lower bulkhead, which seems to be the easiest way of accessing BB.

I removed all 3 plugs and some oil drained out. Not a lot, but it certainly wasn't goo. I refitted the drain plug and then filled by pumping oil in through the vent hole. Suffered the issue of oil coming out the vent hole, but none came out of the lower oil level (allen key plug) hole. After a few attempts to fill by the vent hole I tried to fill at the oil level hole. Virtually none actually went in at this hole, just seemed to pour out as fast as I was pumping it in.

I put the plugs back in and left it till the next day, when I expected the oil to have settled and would be able to pump in more. Removed the orange plug and oil level plug. Oil dripped out of the oil level hole, so I left it until it stopped and then refitted the plugs.

I reckon the BB took about 400ml oil. I've been out for a few runs and BB seems quieter then before the oil change.

The oil I used is this:
Lodexol XFS 80W/140 Fully Synthetic Limited Slip Gear Oil

Top Tip - if you don't remove the long centre tunnel aluminium strip (the one fixed on with 10 bolts) oil coming out of the vent hole is likely to run along this strip and find its way onto the floor pan. If not wiped ip properly it might get to soak into your seat base. Removing the 10 bolts is much quicker than the wiping up I had to do....

Further to Warbirds experience with the BB oil change, I will confirm that 400 ml is about what my gearbox took as well. I also put in 15ml of Liqui Moly MoS2 that I had left over from my Moto Guzzi days, a requirement for the rear gearbox lubrication on them. The oil that came out of my BB was very dark so I assume it had some MoS2 added when it was installed at the factory about 1000 miles ago. My central aluminium strip has only got 8 bolts, have I got the light weight racing model?

I have now resigned myself to BB and belt noise at certain speeds and resonance. The new oil has helped a bit though.

I'm not convinced that the NVH upgrade has done anything other than make it harder to get at the BB.

I must get used to the noises, repeat 100 times.

Donald,

I'm afraid you must get used to the mood of this little lady.
Sometimes she's will whisper in your ears, but at other moments she will scream it out loud.
The problem with her is that you never know in which mood she will be at a certain moment.
You can only handle this, if you fully accept her character.

Enjoy your ride !

Laurens

PS. Any similarity with real ladies is coincidence.