Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Belt noise

No, the standard unit.

Still waiting for B&C to get the kit to add the grease nipple to the unit but after sounding like a bag of bolts at Goodwood it's now gone quiet - for now..

Do we know what exactly the belt is rubbing against to make the noise? My guess would be the side of the pulley, which would stop it running off, if this is the case, then it would seem that the back wheel or the BB are out of alignment, maybe both, so it could be just a 'simple' [but probably time consuming] job of realigning them.

Maybe I'm wrong and the noise caused by something else entirely, but I can't see what.

Has anyone emailed the factory to ask them?

I think this noise is indeed the Drive belt rubbing on the outside edge of the drive sprocket - the element which stops the belt coming off.
Its v annoying - light oil fixed it last time - so hopeing it will again.

Paul, my thought exactly.

With two places to be out of alignment, the rear wheel may be the best place to start.

m3boy, as Paul suggested, adjusting one or both is the permanent answer to the belt noise issue. I do believe the BB was solid mounted to the frame and with the BB upgrade rubber mounting kit, it's still frame mounted and maybe there are no adjustment places and you have to just assume it's where it has to go.

If you assume the BB is where it should be and the belt is rubbing on the outside pulley flange, you would just move the rear axle forward on the right side which would run the belt back toward the middle of the pulley. This is no different than a belt sander belt alignment.

But when you're through with moving the right side forward a bit, be sure you didn't end up over tensioning the belt. As moving forward on the right will very slightly tighten the belt.

If you have the means to jackstand the M3W up safely, you can run the rear wheel with the motor and the belt will just roll inward. A person can then just make minor tweaks with the right side to bring the belt true to the center of the pulley.

I've seen pictures posted here that have no outside flange on the pulley and the belt was more than an 1/8" of an inch off the pulley. If the outside flange is a bolt on, maybe someone took it off to quiet it down rather than adjusting the axle/wheel alignment.

I've also seen two different axle adjusters. I'm guessing the earlier one was the cam/step ones that have notches in the eccentric cams and the later version, again guessing, is the old style bike type with a "U" support and a threaded rod with infinite adjustments versus the notched cam style.

It's not going to be very hard to do the rear axle tweaking and from what I've read posted, it will solve some issues for more than a couple of you.

Good luck with your tweaking...

The early pulleys had no outside flange and for some reason wore out really quickly . Oddly my first pulley (with no flange ) was a lot noisier than the replacement which has been quiet . I think it must be an alignment issue .

Not sure the bit about breakages is true. I have seen one chain break on a racer at Prescott, but it's not a common complaint.

However, the power of the five speed engine would dictate a larger chain and it's a very messy way to transmit power. Just about any maintenance task on the back end is a filthy job, and it needs to be kept clean, lubricated, and adjusted. Not the sort of job that would attract folk I think. So I can understand Morgan's logic.

The flange is the culprit for the noise. I'm very satisfied with that bit.

The newer sprocket with flanges on both sides made a bit of noise from the beginning. My first sprocket only had the inside flange which had never made contact with the belt as the belt, from the very beginning, was riding about 3/8" away from it. The noise in the first one was due to the belt eating the sprocket and the buildup of aluminum debris which made it worse and wore faster as more aluminum dust was created. Spiral of death as it were. When it was finally removed the wear was very deep, as in about 1/8" worn off!

I tried the silicon but that does not last. There is no binder, like an oil, to keep it there. The carrier in most silicon spray is usually an aliphatic naphtha which evaporates almost immediately. So you have the silicon but nothing to keep it there.

Going to try a very lightweight oil such as WD-40 and see where this goes.

Another observation is the the bevel box gear shows absolutely no sign of degradation. Some sort of steel. Too bad the rear sprocket isn't made the same way. It would probably add another 15 lb. or so. The Morgan aluminum sprocket started life as a simple casting then was finished of by milling. A steel rear would have to be totally milled from the very beginning significantly adding to the cost.

OY, what have I started?

Assuming both the BB and rear wheel sprockets are correctly aligned on the same plane but the belt is not tracking in the center of the rear sprocket; why not add a shim between the rear wheel and rear sprocket of the correct thickness to bring them into a true center to center position so that the belt will not ride into the outer flange of the rear sprocket?
I would think this could provide a permanent solution.
Should not be a very difficult task.

Please, not WD40. While it is thin, it has a bad rating as a lubricant. Just about any regular oil is better. If it's ok with the belt - and being oil has to introduce doubts, 3 in 1 with PTFE is a reasonable thin oil and unlike WD40, has good staying power.

The WD part of WD40 means water displacement, and it does it by attracting water to the stuff. You spray something wet that shouldn't be, and it removes the water by attracting the water to itself and the mixture then falling away with the excess. While it does this quite well, the object then needs oiling with a proper oil as any residual WD40 will carry on attracting moisture and is a poor lubricant. WD40 does have uses in the workshop, but far fewer than their hype would have you believe.

Discounting any that think WD40 is the answer, (if you live in the desert and spray often it might be) what do the Harley Davidson crowd dress their belts with?

I have googled around some harley forums on the topic of belt dreesing , and even the official harley product receives very mixed reviews / results.
The impression I got was the majority view was simply try to keep it clean ( i.e. no belt dressing ) - I know this is almost impossible on a M3W , and dont use what seem logical solutions like silicon as dirt clings to them making things worse , and dont use anything that could degrade the belt material. In other words there is no magic solution.
This is why I have been toying with a belt cover of some description , no progress yet.