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

Be aware that on my 2012 if I run the belt in the middle of the rear pulley the belt eats the tire sidewall. When I got the car belt was running 1/8 inch of the pulley on the near side. When I adjusted the belt to the middle it rubs the tire and the belt is the winner. I have checked everything and the alignment seems spot on. It looks like the rear pulley once had an outside flange that was removed. Even being built on a frame jig this car is after all hand assembled. I had a multitude of similar problems when I restored (frame off) my TR3B

Hello

No idea if it would help, but Harley do sell a grease for the belts. It's called Poly-Oil, and according to my non-approved local Harley specialist it considerably improves belt life. He recommends applying the equivalent of an olive stone's worth every 6-8000km

Cheers

Wow that's seriously off!

Either your chassis was built crooked or possibly cracked, the rear swing arm was built crooked or the tire isn't aligned properly in the swing arm left to right on the axle.

Perhaps check the spacers on both sides of the wheel. If on is wider than the other maybe it was assembled incorrectly aligning the wheel too far to the left.

Another option would be to machine two new spacer with the correct width to move the wheel to the right enough to clear the belt when the belt is running on the center of the pully

on my early 2012, i had the rear hub and sprocket replaced. This was called an upgrade for what it is worth.

If everything is aligned properly and the belt is at the correct tension it should be as quiet as it's going to get.

If you picture the belt riding on the pulley at a slight angle there is more pressure on one side than the other, essentially forcing the belt to twist while running over the pulley. This would cause the belt to want to climb to the high side due to the increased friction. Friction = heat- wear & noise.

My belt is true and at the correct tension but still makes a very slight noise when I push my car around the garage with the engine off. This is just the friction of the teeth in the belt meshing with the grooves in the pulley. It's not audible while driving.

After trying all sorts of things, some topical and the rest more substantive, I became very angry. I set aside a day to open up the rear, jack it off the ground and work. It went up about four times before I was satisfied. Making the tension right was the hardest part. Getting the belt to move from one side to the other was easy. Getting it to just ride in the center without hitting the flange was a pain but I persevered. In all instances I powered up the car in first gear while it was off the ground. I even went so far as to make small adjustments while it was running and did the last part by ear. It doesn't hit the tire. It only chirps quietly during deceleration at the low end of the speedometer. In all cases a short test drive under load caused it to go back on the lift for more work until it behaved.

Loosening the tension was a big plus. It was simply too tight. It was making noise no matter where it fell!

Maybe, just maybe, I can leave the small case of 3M ear plugs at home!

The rear sprocket is not making the noise but now the bevel box is the one. I have also noted that with the tension being loosened the bevel box whine is almost gone! On mine it wasn't much to begin with.

Fits and starts. Fits and starts.

Warning the bearings which are not the good ones for the job are very noisy about 5000km more on less
Try to change them And listen

Now that's an interesting observation, Mike..

"If" the belt is too tight in the specs maybe that contributes to the whining on others, too? I can't see something as simple as this not being tried already by the factory, though. It would certainly not help bearing life on that side.

I agree with all you findings Michael H, I found pretty much the same. I arrived at a belt tension of abut 5/8" to 3/4" deflection at the lower mid point with a 10lbs push on the belt. A little tighter and the belt was noisy, less and it made a turbine like noise on acceleration. Alignment of the rear wheel and the belt are also critical, as you also found. I gave the belt and drive gears a good soapy water clean at the same time. I suggest about 15 or 20 ml. of Liqui Moly MoS2, or equivalent, in the bevel gearbox oil as well as it seems to have quietened my BB down a fair bit and cannot do any harm. We may sort out the last 10% of this kit car yet?

Very interesting and thanks for sharing Michael.