- Vehicles
- 8,498
- Built between
- Not published
- Models
- 2
- Recall type
- Equipment
- Initiated by
- Manufacturer
- Owners notified
- 9 December 2023
- Repaired
- 1%
- Unrepaired
- 105
Does this affect my vehicle?
The manufacturer did not publish a build-date range for this recall, so the model and year list below is the only way to tell whether your vehicle is covered.
- Allison Transmission, Inc B3400
- Allison Transmission, Inc B400 Series Transmission
Repair progress
105 of 8,498 vehicles in this recall had still not been repaired as of Q3 2025.
1% repaired — 49 of 8,498 reported
- Owners not reachable
- 12
- Scrapped or exported
- 8,332
Manufacturers file these figures with NHTSA each quarter. Vehicles the manufacturer could not trace, or that have been scrapped or exported, are counted separately and are not included in the unrepaired figure.
What the defect is
Allison Transmission, Inc. (ATI) is recalling certain models B3400xFE_R and B400R, with part numbers B3400xFE_R and B400R. The transmission yoke may separate, resulting in driveshaft separation and a sudden loss of drive power.
What could happen
A sudden loss of drive power can increase the risk of a crash. Additionally, a disabled bus may require an evacuation procedure in an uncontrolled traffic situation, increasing the risk of injury to passengers.
What gets fixed
Dealers will inspect the output yoke bolts, and if necessary, tighten loose output yoke bolts, free of charge. Owner notification letters were mailed December 9, 2023.
Parts involved
- Output Yoke BoltPN29535219Bolt connecting plate 29535213 and yoke 29540327 to output shaft 29540991
Part numbers are as filed by the manufacturer and are listed for reference. Your dealer will confirm the correct part for your vehicle.
Timeline
- Recall reported to NHTSA11 October 2023
- Owners notified9 December 2023
- Latest repair reportQ3 2025 — 1% repaired
Your rights
A safety recall repair is free. Under US federal law the manufacturer must fix a safety defect at no cost to you — no charge for parts, labor or diagnosis — whether or not you are the original owner. A dealer cannot charge you for recall work, and cannot require you to have bought the vehicle from them.
That entitlement is not unlimited. It applies where the vehicle was first sold less than 15 years before the recall was announced — 5 years for tires. Past that a manufacturer may still do the repair free of charge, and many do, but they are no longer obliged to. This recall was reported on 11 October 2023.
To arrange the repair, contact any franchised dealer for the brand. If a dealer refuses the work or tries to charge for it, you can report that to NHTSA at nhtsa.gov/recalls or on 1-888-327-4236.
Manufacturer contact
Owners may contact ATI customer service at 1-317-242-5000. ATI's number for this recall is 2023FA04.
Official source
- Manufacturer's recall number
- 2023FA04
- Recalling manufacturer
- Allison Transmission, Inc.
- Recall initiated by
- MFR
Everything on this page — the models listed, the build dates and the repair figures — comes from the manufacturer's filing to NHTSA and describes the vehicle line as a whole, not any individual car. Only the manufacturer can confirm whether a specific vehicle is affected, and whether its recall work has already been carried out. Check yours by VIN and read the official notice at nhtsa.gov/recalls.
Additional notes
Owners may also contact the National Highway Traffic Safety Administration Vehicle Safety Hotline at 1-888-327-4236 (TTY 1-800-424-9153), or go to www.nhtsa.gov.
Check your own vehicle
This page describes the recall, not any one car. To see which recalls cover a specific vehicle, search by make, model and year.
A VIN lookup here identifies your vehicle and shows recalls issued for that make, model and year. It cannot tell you what is still open on your individual car - only the manufacturer knows that. Search by VIN instead, or check your VIN at nhtsa.gov for whether a recall is still open on your individual car.