Navara hand brake ON while driving

Sounds like your mechanic needs some schooling. Mine is fine.

Is yours a tailshaft handbrake like the GQ's?

F4Phantom,
I cant imagine anyone charging 400 bucks to adjust a handbrake mate.
I think you got done bad somehow, but to be sure, I would get a second opinion. Someone like NRMA (sydney) I dont know what state you are in sorry. They will give you a full report. Keep your receipts cause i think from what i read, you need to get this so called mechanic to fix the damage he caused.
Rear drums burning more than likely means they sre stuffed and your shoes would be too. If it was caused by his lack of knowledge, id make him pay for damage caused.
Cant believe a tradesman could do something like that, he would know they were too tight cause wheels would not turn OR very hard to spin while of ground.

Ange.

$400 sounds like he fitted new brake linings as well. The correct way to adjust a handbrake such as yours is to deadjust or slack off the handbrake adjustment then adjust up the brake shoes until they are just touching the drums. You then adjust the handbrake up to the same adjustment as the drums. The reason it is done this way is because the hand brake is on a mechanical leaver and the foot brake is by hydraulic cylinders, when adjusting the foot brake the cylinders are forced back in and the shoes centred in the drums. If the handbrake is not deajusted first it can hold the shoes out from the hyd cylinders and when the foot brake is applyed the hyd pistons move out to meet the brake shoe and can cause an overadjustment. I think I got this right its been a long time since Tech school. If your brakes have been that hot you may have buggered the lineings. Seized brake cylinders could also cause this problem as the hydraulic pistons are forced out but not pulled back by the brake springs,hope this is of some help.
Regards Nav.