Quick answer

On the Emperor 100 / 100M / 101M mechanical grandfather‑clock movements, the mounting post holes are on the movement’s back plate , arranged to match the three standard mounting posts used in Emperor cases: two lower posts near the bottom corners and one upper center post (a triangular pattern).

Because you’re working with a specific mechanical movement, the exact hole spacing can vary slightly between batches and between the 100, 100M, and 101M versions, so the most reliable method is to measure from the movement itself and compare to the posts in your case.

Where the mounting holes actually are

1. On the movement (back plate)

For these Emperor movements (Hermle‑based 100/100M/101M series):

  • The back plate (the large flat metal plate at the rear of the movement) has three threaded holes or plain holes meant for the mounting posts.
  • Typical layout:
    • Two lower holes : near the bottom left and bottom right corners of the back plate.
    • One upper hole : near the top center of the back plate, often aligned with the center of the movement (above the time/gong trains).
  • These three holes form a triangle that matches the three posts in an Emperor grandfather‑clock case.

In many kits, the movement has plain holes and the nuts go on the inside of the case onto the posts; in others, the holes may be threaded to take screws directly, depending on the exact version and whether it’s a conversion kit (like the #208 kit for 100M).

2. In the clock case

Inside the movement compartment of an Emperor 100/101‑type case you’ll usually find:

  • Three brass or steel posts sticking up from the movement shelf or back board:
    • Two near the front corners (left/right).
    • One near the back center.
  • The movement drops onto these posts so that its three holes line up, then it’s secured with nuts or screws.

If your movement doesn’t line up easily, it’s often because:

  • The movement is rotated 180° (front/back reversed).
  • The movement is a conversion kit intended for a different hole pattern and needs an adapter plate or different post arrangement.

How to locate them on your specific movement

Use this practical checklist:

  1. Remove the movement from the case (if it’s not already out).
  2. Turn it so you’re looking at the back plate (the side opposite the dial).
  3. Look for three holes in a triangular pattern:
    • Two near the bottom corners.
    • One near the top center.
  4. Check whether they are:
    • Plain holes (smooth, no threads) – you’ll use nuts on the inside of the case.
    • Threaded holes – you may screw directly into them from the inside.

If you only see two holes , or the pattern doesn’t match your case’s three posts, you likely have:

  • A different movement version (some later Hermle movements use a 2‑post or 4‑post pattern).
  • A conversion movement that expects a different mounting system.

If you can’t find three obvious holes

Common situations with Emperor 100/100M/101M movements:

  • Older 100/101 movements : usually have the classic 3‑hole triangle on the back plate.
  • 100M and later Hermle 451‑based movements (often sold as Emperor 101M or #208 kits): still use a 3‑point mount, but the hole spacing can be slightly different from very early 100s.
  • Some replacement movements are designed to be bolted from the inside of the case rather than dropped onto posts, so the “holes” might be intended for machine screws rather than post clearance.

If you’re unsure, the safest approach is:

  • Measure the distance between the three posts in your case (center‑to‑center).
  • Measure the distance between the three holes on your movement.
  • If they don’t match within a few millimeters, you’ll need either:
    • A different movement.
    • An adapter plate.
    • To reposition/add posts in the case (ideally with guidance from a clock repair person).

Mini troubleshooting list

If the movement won’t mount cleanly:

  • ✅ Confirm you’re looking at the back plate , not the front or side.
  • ✅ Verify you have three holes , not just branding or decorative holes.
  • ✅ Check orientation: the dial side must face forward , and the winding arbor side usually faces up.
  • ✅ Ensure no washers, brackets, or gong assemblies are blocking the holes.
  • ✅ If using a conversion kit (e.g., #208 for 100M), check its specific instructions; some require slightly different mounting.

TL;DR

  • The mounting post holes on Emperor 100 / 100M / 101M movements are on the back plate.
  • They form a triangle : two lower corner holes and one upper center hole, matching the three posts in the case.
  • Exact spacing can vary by version; if your holes don’t line up with your case posts, you may have a different movement version or a conversion kit that needs adapted mounting.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.