Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Noise from rear on deceleration

I'm hearing a noise from the rear of my M3W that I can only describe as a whirling/swirling noise like something is creating a bit of friction as the rear wheel spins.

It's loudest on deceleration after downshifting to a lower gear as the momentum is slowed down by the transmission. I originally thought the noise was caused by the belt rubbing the tire, but was able to eliminate that as the cause because it only occurs with the clutch engaged. It isn't noticeable when just coasting in neutral.

I can hear it through the seat belt opening at the top of the seat back in the middle.

I'm trying to determine if this is a normal noise or one that justifies a 200 mile trip to the dealer.

Tighten the screws on the back of the seats & around that area

Sounds a bit like what mine was doing. Noise goes away when you dip the clutch. I took mine to the dealer and he said it just needed the belt tightening.

It's the belt. Check for tension. Look for wear. If there is wear, as in, the teeth of the sprocket are wearing down and are very shiny and if you can see that the belt is wearing a 'step' compared to where it doesn't hit then you definitely know what is going on.

To me, this is only the beginning. Once it is doing that then it is only a matter of time until the noise will drive you nuts and the degradation will get worse. When the sprocket is new it ships out with a very hard anodized plating. This is only a few thousandths of an inch thick and is very hard but it does wear and when that is breached then the belt is into the soft aluminum which it will eat like butter.

Aside from having a stone go through it the belt is very tough and should last 100,000 miles. At this point the belt is far tougher than the sprocket.

Search this forum on this subject. Much in there. I'm in most of them. Sore subject...

"Tighten the screws on the back of the seats & around that area" is a cosmetic hit only. When you do that and you remove the seat bottoms and see a lot of black dust then that is a clue. That is pure aluminum from the sprocket.

Tightening the belt will make it wear faster but will alleviate the noise for a bit. The belt should not make noise at all, loose or tight. It's a materials issue not a tension issue.

"Tighten the screws on the back of the seats & around that area" is a cosmetic hit only. When you do that and you remove the seat bottoms and see a lot of black dust then that is a clue. That is pure aluminum from the sprocket.

Tightening the belt will make it wear faster but will alleviate the noise for a bit. The belt should not make noise at all, loose or tight. It's a materials issue not a tension issue.[/quote]

....3000km on my mog & the sprocket is shiny..but its still good, scary thought.
Now its parked till november,its too hot.i guess this coming winter is my last winter to use it.then it must be shipped back to the factory for full upgrades.

Thank you for the detailed explanation about the belt. Greatly appreciated! I originally didn't think it could be the belt, but now I'm not so sure. I only have 700 miles on my M3W afterall. I'll check for tension and the signs of wear that you mentioned.

Dont tighten the belt,it will ruin the sproket.. Mine was fine,till i tightened it,drove it for 2 hrs it made squeeking noises...then i checked the sprocket & it became shinny,so i loosened the belt & its much better...the mog has to have noises..live with it that why,dont adjust many things as you will not make it any better..you will only ruin the sprocket faster

So true. If it suddenly gets quiet then something either broke or fell off! Both have happened to me.

From this forum I have heard that Morgan is now shipping out M3W's with steel sprockets. Or is this a rumor?

I opted to have my last worn out sprocket retooled by Super Max in California. I have it in my hot, sweaty palms and am arranging a time to drive to my dealer to have it swapped out.

I will keep all informed...

2013 and 700 miles!!!! Has it been waiting for repairs that much? I would check the belt tension and maybe the bevel gearbox oil, with that mileage and age you may have "the gunge" in the BB rather than oil. Agree with Michael H about the sprocket wear, although my cars sprockets lasted at least 2000 miles before starting to complain. There is a steel sprocket.

I selected my username a bit prematurely before I became an owner - My M3W was built in August, 2014.

I changed my bevel box oil about a month ago and the BB is reasonably quiet. This noise is different from the bevel box whine, which I think I've trained myself to ignore because I rarely notice it anymore.

Also, the belt seems to be fairly tight already. I tried fiddling with it and couldn't twist more than 1/8" either way.