Ok so im pretty sure my diff has gone...

[Rmachines]

The ringing resonating vibrating grindy noise is getting louder, and fast!  Now i can hear it better im 90% sure its the diff, which is far from unsusual on a golf.   Does any one know what it is that tends to fail?   It is a MK3 TDI box so its cable select, i presume they are all similar to others though.  Its not the first diff thats gone on me, my last one totally failed leaving bits all over the road but that was back in my rolling wheel spins and general fooling about,  it went with no warning. 

so first question is,  its getting louder, started from a distant hum into a full blown grinding,  within about 100 miles.  the last 30 miles has got a lot worse.   Is this more likely to be something like collapsed bearings or fractured gears or... something else?

second question... is it likely to shatter into bits on me?  or do noisy diffs just carry on getting louder and louder untill it seizes up or something?

I have quite a few miles to cover today so im a bit worried 

[Len]

I assume you have checked that there is oil in the gearbox?

[Rmachines]

there is oil in there, level is a bit low and its old, very old.  But due to the sort of noise i think the damage is already done so forking out nearly £20 is £20 less to spend on the near gearbox.   What ya reccon?  I only wanna spend out on oil if its going to either fix it or keep it going alot longer.  Impossible ask i think

[Len]

Was just a long shot mate! If its got oil in and making those kind of noises then its time to change!
If its only diff it may be possible just to change that? 

[Len]

Aint you got spares?

[Rmachines]

No i dont have any TDi spares, i have a 16v cable change box which would fit but ratios would be a pain in the arse!  I really want to keep that one to so i think its deffinatly time to change.