Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 belt squeal on downshifting

Thanks for this info chaps, much appreciated.

Looking at pictures of other owners worn aluminium sprockets, mine is no where near as bad as some of those. 11,000 miles on my car.

Having sort of thrown the towel in on rear wheel adjustment and decided steel sprockets etc needed, when putting the car back together I thought I might as well try some big adjustments just to see what happens. And knock me over with a chocolate biscuit the squealing disappeared on the first run! The belt was running on but not over the outside edge of the rear sprocket so about 4mm away from the inner flange (where it had been previously) plus it was a bit tighter than before. Not a squeal to be had!

But when I pushed the car back into the garage I could hear belt rubbing noises which were coming from the BB sprocket where the belt is on the flange very tightly. I don't think it should be making that noise. Moving the rear sprocket alignment has only made the BB flange rub worse it seems. So I will try some more adjustments soon to try and find a sweet spot of no belt rub noise and no squeal, if that still exists on my car. It would be conveneint not to have to spend money on new parts right now!

If it is running hard against the BB sprocket guide plate the screws will eventually fail and the guide plate will come off. The belt can touch the tyre sidewall or shock absorber if you start to run to the extremes of adjustment. I think any adjustments with a worn alloy sprocket will only be a short term cure. You have done well to keep the alloy sprocket for 11,000 miles, it's usually less than half of that before worn out.

A silicone spray sometimes helps quieten things for a few miles but the real cure is a new sprocket. The belt is usually fine, even after shredding an alloy sprocket. Give the belt a wash with warm soapy water the get the debris off it when fitting a new sprocket, there will be a lot of black dust about.