INSTRUCTION SHEET NO. 375
P/N 29571188
March 20, 2023
Page 1 of 6
SUBJECT:

9-Speed Transmission Range Sensor (TRS) Replacement — In-Chassis Repair

Removal
1. Apply park brake and chock wheels.
2. Drain transmission fluid. Refer to SM8889EN – 9-Speed Service Manual.
3. Remove selector cable from the selector lever.
4. Rotate selector shaft counterclockwise against stop inside transmission to prevent further shaft rotation, then
loosen selector lever nut. Remove selector nut and lever.
5. Remove oil pan and suction filter. Refer to SM8889EN – 9-Speed Service Manual.
6. Disconnect TRS wiring harness connector (refer to Figure 1).

Figure 1.

RC / IS9024EN

6409376

Copyright © 2023 Allison Transmission, Inc. All Rights Reserved.

INSTRUCTION SHEET NO. 375
P/N 29571188
March 20, 2023
Page 2 of 6
7. Remove the two M6 x 1.0 x 17.5 mm bolts (1) holding the detent spring assembly (2) on the main valve
body and set aside (refer to Figure 2).

Figure 2.
8. Rotate the selector shaft counterclockwise until the shifter detent bottoms out in the case. This will allow
access to the TRS retaining bolt. Remove TRS retaining bolt (refer to Figure 3). Discard this bolt and use
the new bolt supplied in the kit.

Figure 3.

Copyright © 2023 Allison Transmission, Inc. All Rights Reserved.

INSTRUCTION SHEET NO. 375
P/N 29571188
March 20, 2023
Page 3 of 6
9. Remove the selector shaft retaining bolt (refer to Figure 4). Discard this bolt and use the new bolt supplied in
the kit.

Figure 4.
10. After the selector shaft retaining bolt has been removed, remove the selector shaft from the main case while
holding the TRS (refer to Figure 5). The TRS can now be removed from the transmission.

Figure 5.

Copyright © 2023 Allison Transmission, Inc. All Rights Reserved.

INSTRUCTION SHEET NO. 375
P/N 29571188
March 20, 2023
Page 4 of 6
11. During removal, if equipped with a park pawl, slide the park pawl apply assembly out of the park pawl guide
along with the TRS (refer to Figure 6).

Figure 6.
12. Rotate the TRS to disconnect the park pawl roller assembly from the TRS (refer to Figure 7).

Figure 7.

Copyright © 2023 Allison Transmission, Inc. All Rights Reserved.

INSTRUCTION SHEET NO. 375
P/N 29571188
March 20, 2023
Page 5 of 6
13. Transfer the park pawl apply assembly to the new TRS to prepare for TRS and park pawl assembly
re-installation.

Figure 8.

TRS Installation — In-chassis:
1. Inspect the selector shaft seal for damage and evidence of leaking and replace if necessary. Selector seal
can be replaced before or after installation of selector shaft depending on the special tool used. Refer to
SM8889EN – 9-Speed Service Manual.
2. If equipped with a park pawl, install the park pawl roller assembly and TRS into the park pawl roller guide
while rotating the TRS into position to accept the selector shaft.
3. While holding the TRS into position, align the selector shaft with main case, slide selector shaft into main
case and through the TRS until it bottoms out in the main case.
4. Install a new clevis pin bolt and torque to 10-13 N·m (88-115 in-lbs).
5. Rotate the selector shaft counterclockwise until the TRS bottoms out in the main case. This will allow access
to the TRS retaining bolt. Install a new TRS retaining bolt and torque to 7-10.4 N·m (62-92 in-lbs).
6. Align detent spring.
7. Install detent spring assembly (2) onto the main valve body (refer to Figure 9). Make sure the detent spring
assembly (2) roller rests on detent lever (3) and the detent spring pin engages the slot (4) in the TRS.
CAUTION: Detent spring must be aligned with slot in the TRS. If not aligned correctly, unwanted vehicle
movement could occur.

Copyright © 2023 Allison Transmission, Inc. All Rights Reserved.

INSTRUCTION SHEET NO. 375
P/N 29571188
March 20, 2023
Page 6 of 6
8. Tighten two M6 x 1.0 x 17.5 mm bolts (1) into the main valve body (refer to Figure 9). Tighten bolts to
10-13 N·m (88-115 in-lbs).

Figure 9.
9. Connect internal harness wiring TRS connector to the TRS (refer to Figure 9).
10. Install suction filter and oil pan. Refer to SM8889EN – 9-Speed Service Manual.
11. Torque oil pan bolts to 24-29 N·m (18-21 lb-ft).
12. Torque drain plug to 30-40 N·m (22-29 lb-ft).
13. Install selector lever. Lever must be fully seated against selector shaft flats.
14. Install selector lever nut finger tight against the lever.
15. Rotate selector shaft clockwise against stop inside transmission to prevent further shaft rotation, then
torque selector lever nut to 20-27 N·m (15-20 lb-ft).
16. Add transmission fluid to proper level cold fill level.
17. With the wheels chocked and parking brake applied, connect to Allison DOC®. Select the “Data Monitor” tab
and review the “PRNDL Range” status in DOC. Turn ignition switch to “ON”. Move the shift selector through
all positions and verify that the DOC “PRNDL Range” matches the gear position on the shift selector.
18. Check that the engine will start with the shift selector in P (Park) or N (Neutral) position. Check that the
engine will not start in any other shift selector position.
19. Start the engine and move the shift selector through all PRNDL positions allowing the transmission to attain
each range to fill the valve body and clutch circuits with fluid. During this step, observe for the presence of a
Range Inhibit Light on the dash. If there is no range inhibit present, continue with adjusting the transmission
fluid level. Refer to 9-Speed Mechanic’s Tips (MT8890EN) or 9-Speed Operator’s Manual (OM8888EN).
20. Test drive and verify the repair.

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