2017 Toyota RAV4 - Do I need this?

[ben43]

is there a need to have transfer case service & rear diff fluid service at 35,000 under normal driving conditions in Nj (no leaks or other problems)

[Purebred]

If specified in your owners manual—yes.
It may void your powertrain warranty if you don’t.
If not required per your manual, it is still good preventative maintenance.

[Nevada_545]

Those fluids should be changed every 15,000 miles if the majority of your driving involves towing, using a car top carrier or heavy loads. It is not required for normal operating conditions but may be recommended by your dealer. See your maintenance guide for details.