I am thinking forced cooling. My current oil is Redline Shockproof by the way , changing to Millers on next change just for the hell of it , plus Dab reccomends it !
Just booked mine in for a service next week and will get Millers EP140 put in - let's see if that makes any difference
Driving several hundred kilometers mostly in pouring rain across parts of Austria and Switzerland in my M3W gave plenty of opportunity to observe the sound produced by the BB and the newly serviced belt. The role of the belt seems to be to transmit the screams and vibrations produced by the BB to the vehicles frame to allow several types of resonances, the tighter the belt is adjusted, the more sound seems to be transmitted, bypassing the damping of the NVH kit. My BB itself, as long as the oil is cold and "thick", is amazingly silent, once at operating temperature, there are several possibilities: pressing the throttle, the whole drivetrain seems silent, at least compared to the engine, up to my personal topspeed. Driving in e.g. a queue, slightly touching the throttle, cruising from slightly above 70 to 110 km/h my BB produces the horrible screaming sounds we all learned to hate. At the upper end some resonances are added. The drivetrain is relatively silent again, when the road descends, pushing and driving the engine. My observations could explain some of the findings Laurens described several posts ago, when describing the sound of his and Rineke's M3W driving the same route, one after the other.
Karl Life is hard in the mountains
2009 silver +4, 2013 red C4P, 2014 yellow M3W gone to a new owner
2012. 7000 miles, of which 3000 on 2nd BB. Noisy, especially anything above 50 mph. Steel sprocket fitted earlier this year. NVH kit fitted, but has not reduced noise. Very noisy transmission, makes it unpleasant to drive any distance unless wearing crash helmets
Via the help of Black Adder I came in contact with a French M3W owner who also had a noisy bevelbox. He opened his unit and found out that the bearings on the pinion shaft where over tighten. From what I read in his answers it looks like that this didn't bring the result he hoped for. I have copied his post and let it translate by Google (sorry my French is not good enough for that)
This is his post on the French forum translated by Google:
I am once again shocked, not by imperfections made by Morgan, then I made a reason, but Quaife, the designer of the Bevel Box.
Why is it so noisy? Why neither Morgan nor Quaife does not bring the solution to the noise so unpleasant for all. I eventually dismantle so simply intend to change the pinion bearings or two bearings that hold the bevel gear alignment which results in the crown.
Being convinced that the noise comes from there, I have removed the nose bridge and found the following:
very important to toil hard spots tending to rotate the wheel by hand. Assumption: Wow, the bearings must be a big hit in the G .....
I undertake to remove the end piece which is fixed to the shaft, and then two shots impact wrench, the clamping nut move a "th" tour, and the gear becomes a facility to run, without any play. Just little noises suggesting they still suffered.
I realize I could have detonated the bevel box, or break a ball or whatever. It's hot, no wonder I was able to recover with bearings squarely HS. I had indeed felt some difficulty in advancing and retracting the three wheels, but then to think that the tapered bearings were tight to death, there they are as strong as Morgan. Now I can even throw the gear and it starts to turn again alone, whereas before, it was hard to turn by hand. Still, I will change the two conical bearings, Koyo, I went to Timken. Once removed, we can only note that this is the tightening that was excessive, the operator did not check whether the gears turning properly, he torqued and that's all.
I'll go all according to the rules of art (the old mechanical) or squeezing in approaching and no play, as soon as I feel a hard point, I will come back slightly.
Following the coming days but there is a good chance that I do not have this p ... noise that spoils partly pleasure. I hope, if only it could be that I shall be delighted.
And for those who feel the soul of an engineer, it's not that hard to intervene. The bearings are: HM88542-HM88510 HM89449-HM89410
Or make intervene the first mechanic that you find, the operation is very simple.
This is his answer to me via a PM
I'm sorry for not knowing properly speak English But I can try with the help of google translation using simple words After emptying It is possible to remove the front of the bevel box through the cockpit
We must remove the two large fixing screws on the frame and the 6 screws connecting with the back of the bevel box is very simple In this front bevel box, there are two tapered roller bearings I noticed that the large nut from the end was far too tight
I had trouble turning the pinion by hand Once disassembled, the raceways were very marked, such as bearings having very many miles. I changed these bearings respecting a moderate tightening necessary for tapered roller bearings. If you have questions, do not hesitate, I will try to help you.
Laurens, do you know if Alain replaced the pinion gear, crush sleeve and shims? If so did he manage to find a supplier for them and some part numbers? There appears to be a new pinion gear in the top photo. If the parts are available it shouldn't be too difficult the set the bevel box up correctly to hopefully run quiet. The bearings, particularly the forward one, don't look brilliant in the photos.
Reading back through the rebuild "Bwitched" did on his BB last year, his problem was caused by a lack of preload of pinion bearings, Alain seems to have had the opposite with them being too tight. Makes you wonder if Quaife are setting the gearboxes at all or just assembling them, the latter is much easier, quicker and cheaper. This would explain why some are quiet and others not.
Laurens, do you know if Alain replaced the pinion gear, crush sleeve and shims? If so did he manage to find a supplier for them and some part numbers? There appears to be a new pinion gear in the top photo. If the parts are available it shouldn't be too difficult the set the bevel box up correctly to hopefully run quiet. The bearings, particularly the forward one, don't look brilliant in the photos.
Reading back through the rebuild "Bwitched" did on his BB last year, his problem was caused by a lack of preload of pinion bearings, Alain seems to have had the opposite with them being too tight. Makes you wonder if Quaife are setting the gearboxes at all or just assembling them, the latter is much easier, quicker and cheaper. This would explain why some are quiet and others not.
I would expect that a pinion shaft fully setup would have a turning resistance of around 16 to 18 inch pounds to turn it. The size of the bearings makes a difference in how much torque is required to spin the shaft. This would be when the nose cone assembly is out, not in the case with the ring gear in tow.
On Ford 9" rears we used to call it the rule of thumb. If you could use your thumb and index finger to spin the shaft, it was probably quite close. Getting a torque wrench to measure less than 20"/# is not the easiest thing to find.
The front pinion bearing looks fried to me. I'm sure it would not have lasted much longer.
Speaking of BB's, did we ever find out what exactly seized up in our Texas friend's BB? I remember he said that it was the first time his wife had driven the M3W and at around 60 mph the rear wheel locked up. Obviously the box seized, but I don't remember what the exact cause was.
) I can confirm that the Bevel box is quite 