Fuhr multipoint door lock gearboxes feature a deadbolt which throws 20mm, except on 25mm and 30mm backset locks, where it throws 14mm. The gearbox measures 220mm x width + 18mm. The latch and deadbolt are both 31mm high and there is 61mm between the bottom of the latch and the top of the deadbolt. Gearboxes are fixed to faceplates with 3 screws. The distance from the top screw to the middle screw is 91mm and the distance from the middle to the bottom screw is 108mm.
Fuhr locks feature a ball bearing and spring pre-fitted. There is a tiny notch on the sliding internal strip that the ball bearing engages (under spring tension) and gives a more positive locking feel when handle operated. If you try a lock without this spring and ball bearing fitted, you'll notice the difference. Some replacement gearboxes on the market are sold without the ball bearing and spring, but all of Duffells' replacement Fuhr gearboxes come with these pre-fitted for a direct swap.
When replacing an existing Fuhr multipoint lock or gearbox, you may find that the latch differs. This can cause problems when the latch locates in the keep. Old versions of Fuhr multipoint lock gearboxes had a latch that was 28mm high, whereas newer versions are 33mm high. If the latch on the old lock is not damaged, it is possible to remove it by undoing the Allen key bolt in the old gearbox, removing it and re-using it in the new lock.
You should also look out for 30mm gearboxes fitted to bifold doors (particularly, Smarts Aluminium doors). These gearboxes do not interchange with the standard 856 gearbox.
We stock a range of associated products for Fuhr 856 - Lift Lever gearboxes, including multipoint door locks, keeps, spindles, handles and accessories.
Operation: Lift Lever
Latch reversal: Undo the screw in the side of the lock case adjacent to the latch. Remove the latch, reverse, reinsert and replace the screw.
To lock the door
1. Lift the handle upwards to engage the locking points.
2. Lock the locking points and main deadbolt (if present) by turning the key.
To unlock the door
1. Unlock the system by turning the key.
2. Push the handle downwards to disengage the locking points and retract the latch.