Hi all, I am getting an annoying noise from the gearbox when under load at low speed in all 6 gears. but especially noticeable in the lower gears due to lack of road noise. Someone has suggested that it is due to the transmission height not being correct where is joined to the support ladder that connects to the differential, does this sound correct? It does not sound like a bearing failing so just wondered it this sounds correct and if anyone knows what the correct height should be?
Many thanks in advance
DRD
If it sounds slightly rattle like dry gears or a bit like a Diesel engine it might be the gearbox backlash?? I believe this is a common occurrence on the NC. I’ve got a 2010 NC2 and sometimes here it when driving slowly in 2nd gear or when loading the engine at low r.p.m and low speed. As I understand it there’s nothing to worry about and it’s down to the design of the 6-speed box. Mine stops making the noise above about 1800 rpm. I hope that helps but best check with an expert if your symptoms are different.
Is it when you are in low gears and come on and off the power, you can hear it growling?
If so that is gearbox lash.
Change the gearbox oil, but it probably won’t improve.
Thanks for the responses guys. I am starting to wonder if it’s the thin metal guard vibrating. Got to get it up in the air and have look, it’s doing my head in. My 44 year old Triumph Stag makes less noise 
Only hear the noise when in gear and moving and not at a standstill?
Yes, only under load when moving. At first thought it was a loose Cat but not to be and sounds if it’s coming from left of Centre rather than rhs where the Cat is.
That’s why I am wondering about transmission height as I had gearbox off to replace the clutch?
Sounds very similar to what mine does at low speeds like around town. Very agricultural ! I just learned to live with it.
There is noticeable noise at low gears like a bearing, mine has always had it but only noticeable with the roof up. I asked a specialist about it and was told it was perfectly normal and due to being in such close proximity to the back axel and gearbox and not much sound insulation. It sounds exactly the same eight years later and I have actually come to like it…….strangely.
I thought gearbox lash was due to misaligned PPF?