Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Muted Bevel Box- Name Your Price?

I put Millers 140 in mine and it took the edge off the noise but certainly was a help rather than a cure.

No downside so give it a go and see what you think.

I have always used 80-140 which demon tweeks sell. EP oil contains sulphur which attacks yellow meatballs like phosphor bronze and I couldn't be arsed to check if the BB contains these yellow metals. It's what the spec says and it's available. I'm convinced the answer to the whine lies elsewhere.

My concern is that Millers is mineral non-synthetic and likewise for the engine it states V twin fully synthetic.

I realise there are additives to synthetic oils but honestly It's a relatively low rev engine so mineral oil in my mind should be fine in both cases.

Surely there's additives in mineral oils too

After reading previous posts on this thread. It would appear that the noise is the result of poorly finished bevel gears.

While not being an engineer, all comments here would seem to point the bevel box being pushed into service long before the gears have been mated.

What solutions are there?
Professional lapping service has been mentioned, but at what cost?
A less protective oil to aid "running in".

Running in, that’s a thing i`ve not heard of for years.

Would it be feasible to get this done by Quaife? Lets say, for a small fee.
So that when(the bevel box)is fitted its sorted.

After all, it would be a lot more expedient and cheaper to do this before fitting than swap them out later.

John, It's not simply a case of lapping - to my understanding it's the position of the pinion in terms of how far into the the meshing gear it's positioned either shimmed out of mesh or reduced shimming to provide the float required with no shimming allowing the pinion further into the drive surface.(depending on bevel box)

These gears seem to be not positioned correctly for the required float but then how adjustable are they anyway

Has anyone blued up the two gears and adjusted in anyway for even wear along the tooth.?

After fitting our new bevel boxes we got the recommendation from MMC to use Mineral 140 oil.

When one of the old boxes started leaking along the seal I changed to Miller mineral 140 in and the leaking was almost gone.
For the noise I didn't hear any difference compared to Red Line.

Got information that MMC is working with more than one company to find a solution for this ongoing problem. But .... they also stated that it is difficult to find a solution.

Let's keep our fingers crossed (what we already do for almost 5 years !! ) that one day we all can enjoy a noiseless bevelbox.

I stay with my opinion that it's the design of the bevel box which cause the problems.
I think as long they stay with this (wrong) design it will be almost impossible to cure the problems.
But ...... I'm not an engineer, so it's just a conclusion after some simple thinking.

Millars better than Redline better than generic 80 / 140

I think it's read that any company involved in lapping in helical gears would have checked and adjusted mesh first.

My own experience is with similar design Moto Guzzi bevel box. This (correctly IMO) uses shims for both pinion and crown wheel mesh.

It's a while since I've done one, but from memory pinion is adjusted first so it's teeth lie across full width of those on crown wheel. The latter then adjusted to obtain central contact pattern within depth of teeth. Maybe just a final check on pinion mesh to ensure contact pattern is central in the other plane.

There was no float adjustment as such, however the back to back pinion support taper rollers were usually adjusted for correct pre-load first via a third set of shims.

This sounds similar to a second hand fairey overdrive box I bought for a landrover I had. It howled when in use. I ended up buying a rotten low mileage landrover that had the overdrive I wanted and replaced the noisey one. The low mileage fairey overdrive was silent in use. It seems properly shimmed and set up they coukd be wuiet in use similar to the bevel box?

That's the problem with folk who fit overdrives to Land Rovers - they just whine.

Sorry grabs coat!