I'm in the UK and not familiar with your particular vehicle.. However, the front gearbox as you call it is probably a transfer unit/case. This transfer case takes power from your auto transmission and transfers it to the front wheels.
You can remove the front propshaft (drive shaft) from the transfer case/front differential and make your vehicle 2 wheel drive. This, supposedly, gives you better mpg.
Answers & Comments
I'm in the UK and not familiar with your particular vehicle..
However, the front gearbox as you call it is probably a transfer unit/case. This transfer case takes power from your auto transmission and transfers it to the front wheels.
You can remove the front propshaft (drive shaft) from the transfer case/front differential and make your vehicle 2 wheel drive. This, supposedly, gives you better mpg.