On my 5th gen, the outside hinge sets the angle of the seat back, at least on my bench seat. The seat back portion of the hinge bears against the the back of the lower portion of the hinge and uses it as a stop.
While looking around for something I could use as a spacer, I measured the width of the hinge slot that the seat back bracket moves in, found a nut the width of the slot, cut a slot through the side of the nut, and slipped it over the back of the slot so the seat back bracket bears against a side of the nut using it as a spacer moving the seat back forward. It seems to work well and has stayed in place. If you could form a piece of metal that would stay in place, that fits over the back of the hinge slot you could make it as thick as needed to set the angle to your desire.
DanKTx
While looking around for something I could use as a spacer, I measured the width of the hinge slot that the seat back bracket moves in, found a nut the width of the slot, cut a slot through the side of the nut, and slipped it over the back of the slot so the seat back bracket bears against a side of the nut using it as a spacer moving the seat back forward. It seems to work well and has stayed in place. If you could form a piece of metal that would stay in place, that fits over the back of the hinge slot you could make it as thick as needed to set the angle to your desire.
DanKTx
