Pajero gearbox issues?

[2freeq]

i was driving down the hume hwy and felt a thud in the car, i couldn`t find anything wrong at the time so i shrugged it off, 200m down the road the thud returned more savage and i pulled over. when i tried to drive off it was like taking off with the handbrake on, so i gave it abit of juice and popped the clutch and i heard a bang followed by a grinding noise. i tried to drive off again and realised i now only have 4th gear, every other gear just revs when i try to take off like its in neutral. the car free rolls ok but i start the car take my foot off the clutch and push the gear stick through the gears without stalling the motor and driving anywhere. 4th gear works fine. i thought i have done a gearbox so i drained the oil out of the box only to find the oil clean, not burnt with no metal chunks or stripped gears. so i was thinking maybe the clutch was shattered but if that was right then why can i take off in 4th gear fine.

Its a 1993 Pajero 2.5 Turbo Diesel Manual

Any help would be welcome.
thanks.

[-Scott-]

i was driving down the hume hwy and felt a thud in the car, i couldn`t find anything wrong at the time so i shrugged it off, 200m down the road the thud returned more savage and i pulled over. when i tried to drive off it was like taking off with the handbrake on, so i gave it abit of juice and popped the clutch and i heard a bang followed by a grinding noise. i tried to drive off again and realised i now only have 4th gear, every other gear just revs when i try to take off like its in neutral. the car free rolls ok but i start the car take my foot off the clutch and push the gear stick through the gears without stalling the motor and driving anywhere. 4th gear works fine. i thought i have done a gearbox so i drained the oil out of the box only to find the oil clean, not burnt with no metal chunks or stripped gears. so i was thinking maybe the clutch was shattered but if that was right then why can i take off in 4th gear fine.

Its a 1993 Pajero 2.5 Turbo Diesel Manual

Any help would be welcome.
thanks.

I'm not much help, but I believe 4th gear is often 1:1, driving through a dog clutch, while all the others use gears on one or more "lay shafts". I guess that somehow you've lost drive through the lay shafts, but I have NFI how that would happen, or what that would mean for the future of your gearbox.

Or I could be completely wrong.

[date]

It sounds to me as if the internal selectors in the gearbox have come adrift, allowing two gears to try to engage at the same time eg gear 2 and 3. This would lock up the box.4th gear is a direct drive, but even so I would expect that the rest of the clusters would be rotating (or trying to do so). Do you have reverse? I would expect that you don't. Whatever the cause, sadly it sounds expensive.

[2freeq]

bugger, oh well, time to rip it out and see what the damage is.