This procedure explains how to replace the 16DP-C Gearbox on CHC EC-1600's. For 16DP-C Gearbox replacements on NGC machines please refer to the Horizontal Gearbox - Replacement - NGC 

This procedure applies to the following part numbers:

• 93-2133A GEARBOX EC-1600/YZT 6K 16DP-C
• 93-2134A GEARBOX EC-1600/YZT 10K 16DP-C
• 93-30-11789 GEARBOX ASSY 16DP-C 50T EC-1600
• 93-30-12836 GEARBOX ASSY 50T 16DP-C EC-500
• 93-30-9983B TRANS EC-1600 6K 16DP-C TBLK
• 93-30-9984B TRANS EC-1600 10K 16DP-C TBLK

A 16DP-50M gearbox [1, 2] has these properties:

• The covers are the same as the covers in the illustration.
• 16DP-50M is engraved on the top of the gearbox housing inside of the enclosure.

A 16DP-C gearbox [3] has these properties:

• The covers are the same as the covers in the illustration.
• 16DP-C is engraved on the top of the gearbox housing inside of the enclosure.

 NOTE: The replacement gearbox does not require an oil pump so it will not come with one.

 NOTE: Updated EC-1600 Service Gearboxes built after 11/2022 may not come with surrounding sheet metal, solenoid, and other components. Please use the existing parts when replacing the gearbox

If the gearbox has an enclosure [1], remove it.

If the machine has Through-Spindle Coolant (TSC) [2.3], remove the rotary or bearingless union, hoses and wiring.

NOTE: Refer to the VMC, HMC - 50-Taper - Belt Drive - TSC - Bearing Union - Upgrade to Bearingless Union Procedure for further details. 

Jog the Y-Axis to a position that lets you easily remove the gearbox. If there is tooling in the spindle, remove it.

Record the value of Parameter 76. Change Parameter 76 to 999999.

Push [POWER OFF].

Set the main circuit breaker to the OFF position. Lock the main circuit breaker. Use an approved lock with an approved safety tag.

Disconnect the Y-Axis way cover assemblies. Hold the upper way cover in position with C-clamps.

If the TRP has enclosure panels, remove them. Make sure not to damage the spindle lubrication tubing.

Put labels on the tubes and cables and disconnect them.

Put an applicable strap from a hoist around the TRP assembly and loosen the TRP screws.

NOTE: Record the quantities and locations of the shims. These are typical. Your counts can be different.

• [3] 0.015 Shim Washer ( Quantity: 3).
• [2] 0.010 Shim Washer (Quantity: 2).
• [1] 0.093 Nylon Washer (Quantity: 1).

Remove the TRP assembly.

Remove the electrical cover plate on the spindle. Record the location of the cables and remove the cables [1] from the spindle connection block [2].

Disconnect the spindle cables from electrical control box.

Disconnect the rest of the cables and hoses from the gearbox and the solenoid assembly.

If the gearbox has lower enclosure panels, remove them.

Install a threaded lifting eyebolt [1] into the top of the motor plate. The rear lifting point [2] is attached to the gearbox assembly. Attach the chain sling to the lifting points for the gearbox. Make sure the chain or strap can lift 300 lb (136 kg) or more.

Loosen the (4) gearbox screws. Make sure to support the gearbox assembly with the hoist. Make sure not to adjust the jack screws during the removal.

Remove the (4) gearbox screws. Remove the gearbox from the machine.

Install the spindle belt [1] on the spindle.

Install an eyebolt into the top of the motor plate. The rear lifting point is part of the gearbox assembly. Attach an applicable strap or chain to the lift points. Make sure the chain or strap can lift 300 lb (136 kg) or more.

Install the (4) gearbox screws [2]. Lightly tighten the gearbox screws and slowly lower the gearbox.

CAUTION: The 16DP-C Gearbox does not have slotted holes for the mounting bolts for the gearbox. Make sure to keep the gearbox level for the installation.

Adjust the tension on the spindle drive belt.

NOTE: Refer to the Spindle Drive Belt - Tension Adjustment - Gates Sonic - Mill Procedure.

Meter Instructions for more information.

Tighten the bolts when the belt tension is correct.

NOTE: Refer to Haas Fastener Torque Specifications for correct torque values.

Remove the threaded lifting eyebolt.

 NOTE: Updated EC-1600 Service Gearboxes built after 11/2022 may not come with surrounding sheet metal, solenoid, and other components. Please use the existing parts when replacing the gearbox

Connect all of the cables and hoses to the gearbox.

Install the lower enclosure panels and the solenoid assembly. Connect all of the electrical connections and install the electrical cover plate.

Put the TRP [1] assembly into place.

Put the correct number of washers and spacers in the recorded locations.

Install and tighten the TRP screws.

NOTE: Refer to Haas Fastener Torque Specifications for correcttorque values.

If the TRP has enclosure panels [2], install them. Connect the TRP air lines and proximity switches.

Do this step if the gearbox you removed is a 16DP-50M.

Disconnect the connector that has the label 950 LOW GEARBOX OIL PRESS STATUS. Refer to Molex Connector - Change Pin Locations.

CAUTION: Do not use a different tool to change the pin locations.

This can cause damage to the pins.

Change these pin locations:

• 1. Move the Molex pin in position 3 to position 4.
• 2. Move the Molex pin in position 1 to position 2.

Install the molex connector to the position with the label 950 LOW GEARBOX OIL PRESS STATUS. Install the Molex connector from the gearbox to the Molex connector. Make sure the pins on the Molex connectors align.

Install the used fan assembly and enclosure panels to the gearbox.

If the machine has TSC [1,2], install the rotary or bearingless union, hoses, and wiring.

NOTE: Refer to the VMC, HMC - 50-Taper - Belt Drive - TSC - Bearing Union - Upgrade to Bearingless Union Procedure for further details. 

Remove the C-Clamps that hold the way covers [3] in position and connect them to the spindle assembly.

Change Parameter 76 to the recorded value. Open the primary air valve.

Replace the Spindle Encoder Belt. If you do not have a non-contact encoder, install the encoder assembly, encoder belt, and cover plate.