Is it gearbox?? any ideas

[younglion]

Hi guys, i got a question. i have a vr commodore and when i accelerate from a standing start something grinds at the back of the car i think its either gearbox or diff. and when i turn right and try to accelerate out of a corner the revs drop for a second then pick up again, is this sounding like a buggered gearbox???? any help would be great?

 

[volotre]

The grinding noise could be centre bearing in the tailshaft. If it only happens when you floor it off the line then that's where I'd look first. They have a two piece tailshaft that has a bearing in the centre and it's common for them to fail, usually a bit of vibration when you gun it from a stand still as well. Pretty easy to do yourself (check the how to tech stuff on this site) and the bearing is around $40 - $30 bucks.
The revs dropping thing could just be the auto, they're not the best box out there and their shifting can be a bit erratic so maybe it's just a bit slow on the kickdown.