diff --git a/include/hexagram/tacho.h b/include/hexagram/tacho.h
index 3a2b2cb..38c479e 100644
--- a/include/hexagram/tacho.h
+++ b/include/hexagram/tacho.h
@@ -29,6 +29,8 @@ int hexagram_tacho_init(hexagram_tacho *tacho,
                         double redline,
                         double rpm_max);
 
+void hexagram_tacho_set_gear(hexagram_tacho *tacho, hexagram_trans_gear gear);
+
 int hexagram_tacho_shift_indicator_init(hexagram_tacho_shift_indicator *shift,
                                         double x,
                                         double y,
diff --git a/src/tacho.c b/src/tacho.c
index c753dd3..717191e 100644
--- a/src/tacho.c
+++ b/src/tacho.c
@@ -166,6 +166,30 @@ error_dial_init:
     return -1;
 }
 
+void hexagram_tacho_set_gear(hexagram_tacho *tacho, hexagram_trans_gear gear) {
+    switch (gear) {
+        case HEXAGRAM_TRANS_GEAR_S:
+        case HEXAGRAM_TRANS_GEAR_D:
+        case HEXAGRAM_TRANS_GEAR_P:
+        case HEXAGRAM_TRANS_GEAR_R:
+        case HEXAGRAM_TRANS_GEAR_N:
+        case HEXAGRAM_TRANS_GEAR_1:
+        case HEXAGRAM_TRANS_GEAR_2:
+        case HEXAGRAM_TRANS_GEAR_3:
+        case HEXAGRAM_TRANS_GEAR_4:
+        case HEXAGRAM_TRANS_GEAR_5:
+        case HEXAGRAM_TRANS_GEAR_6:
+        case HEXAGRAM_TRANS_GEAR_7:
+        case HEXAGRAM_TRANS_GEAR_8:
+        case HEXAGRAM_TRANS_GEAR_9:
+        case HEXAGRAM_TRANS_GEAR_10:
+            tacho->gear = gear;
+
+        default:
+            return;
+    }
+}
+
 #define LIGHT_LEVEL_COUNT  5
 #define LIGHT_WIDTH       48
 #define LIGHT_HEIGHT      12