Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Drive belt tooth jumping? maybe a solution...

There is this comment in the M3W Buyer's Guide about teeth jumping that may, or may not, be relevant to owners wondering if they have an issue:

A loud bang when accelerating from standstill is caused by excessive
vertical movement of the bevel box NVH bracket causing it to hit the
chassis. This is often mistakenly diagnosed as the drive belt slipping a
tooth on the drive sprocket. Morgan’s solution for this is to run very
tight drive belt tension.

Remember this is just my opinion - not gospel!

I’m a real “ Gear head “ your work is technically incredible . I have 2014 m3w. Getting belt slip way to much .
Have new belt (-50 miles ) and new poly coated sprocket .
Love your set up 👍🏼 And vid . Incredible. Not your typical crazy crazy inaccurate advice I find here . Lol ive used similar set ups on different rides ! In all likelihood that roller wheel will last 100 years ! Btw

On Harleys when you jump the rear sprocket with the belt, you will usually snap the belt at the same time.

If a belt seems tight to you, just imagine how far it would have to stretch to actually jump the teeth on the sprocket. Carbon fiber belts do not stretch, they will break as the belt tries to climb the teeth on the belt.

The only way in my opinion for the belt to jump, would be a VERY loose belt and then it would probably be jumping all the time instead of just on a hard accel.

My gut tells me that it's something else on the M3W causing the loud noise, not the belt jumping the teeth. Don't have a M3W and this is only my opinion based on my knowledge of other belt driven hard vehicles.

Of course, this is not a belt jump.
It is a slip of a special HD clutch, which is located together with the vibration damper.
It is possible that the spring pressure is weaker or the motor torque is manipulated.
Sincerely

If you look at the M3W transmission from 2014 cars onwards, you will see that all those parts you mention are not in it. Almost all pre-2014 cars must have been modified to the Centa system by now, or done very few miles. I do agree that it is very unlikely to be the drive belt jumping a tooth.

Of course it’s not belt drive slipping ? I found that absolutely hilarious. Like the submachinegun sound from rear isn’t obvious???The one commenter who dosent even own a M3w is all full of advice and more ! Lol
I doll out technical advice on Lamborghinis , all the time . I don’t own one ? I just like to help . Ha all good 👍🏼 My belt slips like a bandit on my hard Get up and goes . If I don’t blast 💥 from stop . It dosent slip. So I realized I’m Not in a 1969 GTO . And that has helped with belt slip issue …. More than any Spot on serious helpful advice here . Lol 😂

I think one of MMC's solutions to belt slip is to use a hard runner compound in the rear tire and make sure it is not a symmetrical tread pattern so it slips easily and in having the tire slip there is less pressure on the belt!. Just a thought :-)

I almost got stuck at a traffic light on a slight grade in the shade under a grove of fir trees. Shady, mossy and fir needles on the road; M3W did not want to go forward if I gave it to much fuel. I decided to change the rear tire to one with softer rubber and symmetrical tread pattern and now much less slip but the NVH banging around was louder and more frequent. Solution was the Bleazey NVH Delete Kit. Now the back end of the MOG is happy.

This is not a helpful post IMO. Also, not in the spirit of TalkMorgan.

+1. I havent seen anyone prove that their toothed belt is "slipping" aka jumping or breaking its teeth - and folk more knowledgable than me in the motorbike world seem to laugh at that idea My car's "submachinegun sound" was solved by the PB BB mount replacing the so-called NVH kit. But it looks like their may be other problems / solutions at play.