Gearbox Noise

[willis 18 1 Cars]

I have a BE3 gearbox fitted to my 1990 1.6. I have noticed it sounds like it is rattling/knocking when idling in neutral. When I put the clutch fully in it goes. The gearbox works well, it is smooth and never jumps out of gear.

 

Is this likely to be the thrust bearing or something more?

 

Also, completely unrelated to this, but I've just had an old large bore full exhaust, scorpion I think, taken off and had a standard one put on. I thought my valve stem oil seals needed replacing as it was smoking once warmed up but now this issue has disappeared! It also idles much better due to increased back pressure I guess?

 

Thanks

[luggy 13]

Before condeming the thrust bearing seeing that you've replaced the exhaust it could be the exhaust touching the gear linkage, gear linkage mount can be adjusted as its bolted to the subframe, once adjusted don't do the nut up too tight or it'll shear ​

[Tom Fenton 1,541]

The noise you describe is usually the input shaft bearing chattering. As soon as you press the clutch you stop driving the gearbox hence the noise stops.

Its nothing to really worry about, the gearbox is being driven under no load lence the bearing chatters. If it made a noise when driving under load e.g. in a gear driving along then it would be a problem, but I will guess that it doesn't.

I've had numerous gearboxes do this over the years and never got any worse or caused me a problem.

[willis 18 1 Cars]

Thanks, I'll check it out driving.

 

I've only got the car back in the road yesterday. It was sorn'd for the winter and I didn't notice it before.