Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Bevel box oil seal failure

Both my bevel boxes were replaced under warranty so presumably only filled to the recommended level. I have changed the oil in the latest one and filled it to the orange plug, have done 2000 miles since and it seems OK, some oil out of the breather in the orange plug that is all.

I had thought that maybe mine failed due to the additive MMC were adding to the bevel box as they were both of that era, but as the OP is reporting failure from a new car perhaps that was not the cause.

Thanks for the update Rog - just what I was after!

My second bevel box has been emptied four times during the first 15 000 km and not drained until now (10000km) with upgrade of oil near the drain plug, I vai soon emptied again with gearbox.

Since the BB gets so hot it needs all the air volume available to counteract the increase in air pressure. Over filled gearboxes tend to blow out oil seals

The bb has a breather, there is no air pressure whatsoever

Mine is up to the orange plug and I have just done 1500 miles in 4 days. 2 of the legs were 900kms in one go.

Fill it and go for it.

So I removed the interior and got to the BB for my first time last Friday and found the orange plug about 50% unscrewed. Quite a bit of oil-spill evidence, but it has never dripped onto the floor. Seems it had VERY little in it, despite having supposedly had the oil changed at the last service (500 miles ago). I added approx. 300-350cc of fresh 85W140 Omega 690 gear oil and unsurprisingly the BB runs much quieter than it did before.

I had noticed more noise since the Centa was fitted at the same service, but I put the increased whining down to the fact that the compensator no longer rattled like a bar-steward, so I thought little more about it. However, it is now clear that the BB was very low on oil, so hopefully little damage done.

Check the BB regularly !