life expectancy of LT77 gearbox once fifth gear whine starts

[feraldisco]

I've got a 1993 200tdi Disco with 250,000ks which has been a very reliable machine. The LT77 g/box has developed a fifth gear whine. I'm wondering if anyone has driven a car with such a whine for years without problems? Am I likely to get some warning of complete failure (i.e. whine getting louder) or might it suddenly cr*p itself one day?

Btw, my acetone experiment (100mls in 80litres diesel) is going well - reduced smoke and smoother/better performance...

[sclarke]

My old Disco had the same prob.
Put Penrite Gear oil in it, Ask Penrite what they recommend for a Landy.
Its thin like tranny oil but Gold and slippery...