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

And you can edit the entry for my car. My dealers wrench says mine is one of the quietest he's heard, but it's still noticeable to me. Of course I've never heard anybody else's. Mine is noisy at 45-60 under light load. It's quiet when cold at any speed, but after 3-5 miles, it has that supercharger whine.

also would be worthwhile asking to which level in the bevelbox the oil is filled. some fill via the breather all the way up, others only via the filling hole and not higher. difference is 0,4l i guess. does it make a difference in noise level?

If indeed the side hole is called the "fill hole", then that kind of answers the question as to how high the level is meant to be.

I can't think of any reason to go to all the trouble to engineer and machine a large hole on the side if it's meant to be filled to the top via the vent hole.

Agreed...the vent hole is meant to have air below it that is allowed to expand, not oil to expand and weep out.

sure, but look at the thread re. this question. Nobody agrees on where and how much, not even the dealers.

I think having all these issues with the BB, noise, locking up etc, the dealers have been second guessing themselves as to what it the correct fill level. I believe they're just afraid to take a stand. This boils down to MMC not being definitive in the maintenance manual and clearly stating the proper level.

But when it comes down to it, noises and issues aside, the fill level is always the side fill plug hole.

Lets say you have a standard 4-wheel vehicle with a solid rear axle and third member, there is a fill plug about the level of the mid pinion shaft range. They also have a vent on top. Who would "ever" consider filling the entire third member with oil through the vent??? They have the very same ring and pinion design, so why would the BB be any different.

When there is no side fill plug, I've never seen one without a dip stick attached to the bottom of the cap.

In most cases, seals are really not designed to be flooded with oil, but to retain oil as it gets splashed in their general area.

Again with all the issues, I think that anything was open to being tried, including filling the entire BB with oil.

Keep in mind the amount of extra parasitic drag when this thick of oil is constantly being pushed around by the ring/pinion when the BB is completely filled to the brim.

As has been pointed out a few times, I have no skin in the game, but I would only fill to the level of the side fill hole and then worry about other means to quiet it down. I wouldn't even think about filling higher than the side. I might fill through the vent hole if it's easier to access, but when oil runs out the side hole, that's full and I'd put the plugs back in and call it done.

This is a new Honda Goldwing GL1800 final drive assembly. The large hole on the side is the fill hole, the lower is the drain and the upper chrome top hat is the vent.

You can see that when FULL, the level is just about 1/3 up from the bottom of the case. The Honda final drive is setup very similarly to the BB, in that the pinion is centered in the ring gear, unlike most conventional car third members where the pinion shaft is about a third the way to being centered.

very comprehensive as usual, thanks Dan

Hello all, I have just recently purchased "Little Nelly" the sport grey car from Tony. It's a wonderful car, and I am still getting used to the attention. I have been driving for around 200 miles so far and just about getting used to her, starting to relax into the seat, road positioning etc. The only thing I am not taking a liking to is the bevel box backlash, and clunking.

Obviously its fine under load, but "clonks, and rattles" at light load, or next to none.

There is some noise, but not something that detracts from the whole ambience of this crazy little tub of fun.

It looks a fairly straightforward item to replace, I have already adjusted the belt tension as it was occasioning touching the lover chassis rail, so I guess its just some 13mm spanner and sockets, and out it comes.

So my questions are;
1. Is it dangerous?

2. Do Quaife offer a service for these units, their site seems to suggest it might.
http://quaife.co.uk/how-we-do-it/support-and-servicing/

3. If the service idea is a non starter, where's the best place to purchase one, and likely cost.

4. Where do all the old units go, that have been swapped out. I wouldn't mind pulling one apart to see what the issues are, or even refurbishing one, with some of my local engineering shops that I get along with?

P.S How do we embed pictures into the posts?

The rattle and clonk sounds more like the original design of the compensator than the bevel box. The bevel box noise is more like that a straight cut gearbox sounds like.

You need to keep the engine revs over 2750, this may improve/ eliminate the rattle.

+1 Rog, it needs to be kept on the boil as it were.