Pajero Owners Club of South Africa

Hi there, I'm new to the club and already impressed. I have a 2800 turbo intercooler DID Pajero. When I select drive and try to pull off, the revs rise but no forward motion. I give some more power and then the car starts moving. It is as if the box is "slipping". When I do eventually get going, the box runs quickly through the gears but hardly ever goes to overdrive (o/d button on gearshifter) The motor revs but hardly any speed. I want to change the transmission fluid. Could someone PLEASE help me with the quantity and grade of transmission fluid I must use. I drained some fluid from the box and it is very dark and smells burnt. Any info and suggestions would greatly be appreciated. Thanks in advance.
Regards,
Leonz

there is a plug underneath to drain and a plug on top to fill.

( do it after a drive when the oil is hot - drain - wait 30 minutes to cool - fill - check for leaks after 2 days )