250 Gearbox sound around 50mph

Does anyone have any idea of cost to have a gearbox removed, rebuilt and refitted?

I see reconditioned boxes on ebay etc but I have no idea what the labour would be to remove one.

Is it beyond the realms of DIY?

 

Mine whines too, only subtly but it has gotten worse since i picked it up a year and a half ago, perhaps i didn't notice it then though... So going to get a gearbox oil change in spring next year. Can anyone recommend any particular oil?

Mine's got 112k miles so could be the fleet leader in terms of milage, though indications are that it hasn't been driven hard over most of those miles, mainly motorway - until i got it at 100k. I'm waiting for any serious degradation/issues before I consider changing the box! I'll let you know how i get on in the coming year Charlie.

 

I had this and it was hard to tell where the noise was coming from when travelling in the car; except that it was linked to speed of the wheels/gearbox output, rather than revs etc...
Secured the car with the front wheels in the air, started it up and engaged the gears, this noise was surprisingly loud in 3rd gear at idle revs. Increased the revs slightly and the noise was deafening! The noise was definitely coming from the gearbox, though still hard to tell if it was the box or the dif. I left it a few months and now the noise has completely gone, the whole time my gearbox has felt fine, so now i am just pretending this never happened