Brother GTX-4 Service Manual page 205

(10) Remove the retaining ring and detach the shaft, tension pulley and tension pulley bearing from the platen belt
tension adjustment mechanism.
Assembly
(1) To perform the assembly, take the reverse procedures to disassembly operation.
<IMPORTANT>

Adjust tension applied to the belts upon reference to "6-1-5. Tension adjustment for platen and deceleration belts".
(2) Attach the shaft, tension pulley and tension pulley bearing to the platen belt tension adjustment mechanism and
re-engage the retaining ring.
<IMPORTANT>

Always replace retaining ring with new part instead of reusing the rings removed.

Confirm smooth rotation of the tension pulley.
Shaft
Retaining ring
Tension pulley bearing
Tension pulley
Shaft
Retaining ring
Tension pulley bearing
Tension pulley
Disassembly / Replacement / Adjustment
6-14