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

with my first belt I started using three spray Teflon wurth brand that gave a good result after the silicone does not last very long and Marseille soap with olive oil I actually rubbed on the belt after sunrise to crick the back of three wheel motor running with the first gear clancher, it lasts as long as Teflon and not cost much.

Teflon may be a good temporary fix. A greaseless lubricant. Will check it out.

I wonder if powdered rosin as used by gymnasts ,climbers & dancers would do any good. In solid form known as belt stick its rubbed on flat drive belts to reduce slip.

Tim

Wouldn't rosin make the pulley stickier? This could exacerbate the noise, rather like a violin bow........

Very much so, I'm afraid. Most of the noise generated comes from the belt releasing.

This seems to indicate that belt tension may be the cause rather than alignment.

Planenut, how much did you slacken off the belt to stop the squeaking?

I have tensioned the belt to about 5/8" to 3/4" deflection with a 10lbs load at the mid point on the lower run. It's not easy to gauge it accurately without the correct Harley tool, you need 3 hands to do it with a straight edge and spring scales. Essentially, try it a little slack rather than tight but not too much. Give the belt and gears a clean with soapy water and align the rear wheel using the axle adjusters. My car was bad but seems to be OK now, so one or all of those things has sorted it, for now. The sprays and oils are only a temporary fix in my experience.

The belt shouldn't rub on either side of the pulley flanges. It should run on the middle of the pulley.

Its a bit of a process to true the belt. First loosen the axle nut then use the two adjustment nuts on the end of the swing arm to adjust the angle of the wheel assembly until the belt runs in the middle of the pulley.

Either spin the wheel by hand or run the car with the rear wheel elevated in first gear. Make adjustments and repeat the process until the belt runs true.

Finally check belt tension and confirm the belt is still running true, then tighten everything up.

So, if the belt runs true and in the middle, does that mean that there will be no noise at all? If it is as [relatively] easy as that, why are so many cars suffering from so much noise?

Good question Paul...

But as I've suggested, starting with the belt properly aligned is a good staring point. If it's noisy after the belt is properly centered, address the next thing that could cause it.

But to be honest with you, I've been on a few Harley forums for many years and I've never heard of anyone complaining about a noisy rear belt. That doesn't mean there aren't some, but not enough of them to be an item to start a thread about.

I really can't put my finger on the problem for your noisy belts, but there has to be a reason. Lubricating or coating the belt with secondary "stuff" is not the true long term answer.

We use 8mm Polychain profiles on our machines and they run 24/7/365 and we have no complaints about noisy belts. As I've shown on another thread, we water jet cut all of our pulleys based on profiles supplied by Gates. Our pulleys are not sent out for coating, we run them bare aluminium. They are also a bit rough as we run our water jet at a mid speed on the cutting path.

As far as belt tension goes, I'm not going to offer, but I can tell you that if they are too loose, they tend to climb the teeth creating a LOT more pressure on the belt and that's when most belts break; running too loose.

On my Willys with the GMC 6.71 belt driven blower, I had to drill my pulleys with very fine bits to release the air trapped under the belt as they turned. In my case I had a Gilmore 1/2" pitch 3" wide belt and that did trap air in the teeth. This created lot of extra "unwanted noise. I say unwanted as it's quite a nice noise to have is the whine of the GMC blower setting on top of your big V-8. Some guys take out their nice quiet timing chains and replace them with straight cut gear drives for their cams just to get that "blower whine".

I'm sure though at only 1.5" wide on the belt that it's not going to be air trapped making the noise.

But if MMC is having their pulleys made up on a CNC mill, there could be some type of profile inaccuracies that could be the cause too. They buy the belts from Gates so they're locked in there. So it has to be the pulleys, alignment or tension etc.

Sorry for rambling. My fingers get typing and I can't shut them up!