That depends what you have done so far; coolant and brake fluid should be flushed every 30k or so. Timing belt is at 90-100k, air filter every 20k or so, trans fluid I like to change every 25-30k.
If you have no service records showing the differential/transmission fluid has been changed then by all means. Hornsfan 10609 recommends every 25k-30k depending on how you drive her I would guess.