Just revisiting this thread because my car is currently with a dealer to have the BB tested and then either changed or fixed.
Interesting that Rufus3 commented at the lack of oil in the box.
Having spoken to a gearbox expert who re-manufactures Ford 5 speed boxes with special ratios, he commented that the most likely reason was that the gears hadn't been honed, Quaife don't normally do this, as it is unnecessary for racing applications, and maybe it would cost more to have it done on all the Morgan Bevel Boxes, I don't know. Hence the reason that Morgan won't consider any warranty work until at least a thousand miles have passed. The lapping of the bearing surfaces is being done by the owner on the road.
As a matter of interest, I found that my noise was worst at between 65 - 80mph, lessening over 80mph. But it very definitely became worse the longer the journey, and anyway, after about 25 miles fast cruising. I guess the oil heated up and thinned down enough that it wasn't working so well on the gear teeth.
Re-reading the bits about the 'climbing' oil, I could understand that it would form a film between gear teeth, but how would it get on in lubricating the bearings, which are a much tighter tolerance? Is it too thick to get into a bearing or is that the function of the weight of it?
