Diagnosis please

[WNE552]

Over the years my 1958 Minor has had many rattles that took time to identify and cure but there is now one that has been defeating me for several months.It started faintly as an intermittent tinkling noise but has become louder some of the time.
It is not present when the car is stationary with the engine running nor when in reverse. There is no problem with engaging any gear and doesn't appear to be any clutch slip (it stalls if you engage 3rd while stationary for example). On a quiet road, putting the car in neutral going downhill stopped the noise but it restarted when put back in gear. Car is to original 948 spec.
Any diagnoses appreciated.

[chesney]

It could be the exhaust mounting, or a baffle come loose in the silencer?

[SteveClem]

One of mine did that a few years back. Turned out to be an exhaust baffle, but could have been lots of other things I suppose.

[drivewasher]

To test for exhaust baffle loose hit the silencer with a rubber, hide or plastic hammer and listen for the tinkle

[SteveClem]

Yes the word 'tinkle' could be the clue. Exactly the noise mine made.

[simmitc]

Possibly a UJ on the prop shaft. Simple enough to check for play.

[kennatt]

is it gone when you put the clutch in,and there when clutch is out,could be the first sign of a worn first motion shaft bearing,out of gear in neutral its turning with engine running, clutch in and it stops,had the same on a couple of boxes over the years.

[WNE552]

Thanks for the suggestions - I'll check the exhaust and test for baffle noise then report back

[WNE552]

I've now checked the exhaust mountings and all secure. Also tapped the exhaust with a rubber hammer but no tinkling sound so this suggests the fault is within the gearbox. As regards a fault with the U/J why would this only be intermittent? I would think that it would be noisy in reverse as well as forward gears?

[simmitc]

The UJs may wear unevenly. Sometimes the noise is heard only when moving off, sometimes as load is applied and removed whilst driving. It's worth checking by reaching underneath and turning the shaft back and forth. Take no notice of backlash from the diff, just see if there is any movement between the shaft and the yoke. It's much easier than changing a box! If it isn't the fault, then it cost you nothing, and took only couple of minutes to rule out.

[simmitc]

The UJs may wear unevenly. Sometimes the noise is heard only when moving off, sometimes as load is applied and removed whilst driving. It's worth checking by reaching underneath and turning the shaft back and forth. Take no notice of backlash from the diff, just see if there is any movement between the shaft and the yoke. It's much easier than changing a box! If it isn't the fault, then it cost you nothing, and took only couple of minutes to rule out.

[bmcecosse]

Don't just twist the shaft - lift it at each UJ to see if there is any play in the UJ...