Replacing an Old Gateman III Digital Lock with a Yale YDM 3109A 70mm Backset

The Gateman III was one of the most popular digital door locks in New Zealand over a decade ago. It was a solid and reliable lock for its time, but it has now been discontinued for quite a while.

One common issue we see today is that there is no current digital lock model that uses the exact same drilling template as the old Gateman III. This can make replacement tricky, especially for homeowners who want to avoid patching, repainting, or replacing the whole door.

For this job, we replaced an old Gateman III digital lock on a timber door with a Yale YDM 3109A 70mm backset digital mortise lock.

Over the years, we have seen many different Gateman III installations. Back when these locks were commonly installed, not every installer followed the standard drilling template.

As a result, some doors have extra or unnecessary holes behind the lock body. These holes can be difficult to cover when replacing the lock with a newer model. That is why choosing the right replacement lock is important. A lock that is too small, too narrow, or uses a difference backset may leave old holes exposed.

The Yale YDM 3109A 70mm backset is one of the few digital mortise locks that can work well as a replacement for an old Gateman III in many situations. 

For this installation, the Yale 3109A covered all the existing bore holes and strike holes from the old lock. Because the Yale 3109A uses a quite different drilling template, additional mortise cuts and new holes were required on both the door and the frame. This is not a straight swap, but with careful drilling and fitting, it can be a tidy and practical upgrade.

As the Yale YDM 3109A is slightly slimmer than the old Gateman III, there may be some unpainted surface or marks left behind where the old lock used to sit. On timber doors, this usually means some minor touch-up may be needed after installation, especially if the door has faded or changed colour over time around the old lock.

If you still have an old Gateman III digital lock and are unsure what can replace it, we can help check the door and recommend a suitable option.

In many cases, the Yale YDM 3109A 70mm backset can be a good replacement choice, but compatibility depends on the existing holes, door material, backset, and frame condition.

For the best advice, please send us clear photos of the inside, outside, door edge, and strike plate area.