GM bulletin N232403290
What it saysService Update - Certain vehicles may have a condition in which the incorrect thrust washer was installed in the transmission input carrier. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Jun 29, 2023, received Jun 30, 2023, about the power train. It names 2 model years across Chevrolet and GMC (2023). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
One page for every brand it was filed under. Each brand’s bulletins: Chevrolet · GMC.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationPicked out of NHTSA’s summary below, word for word. The document itself is the record, and the dealer checks the VIN.
Service Update - Certain vehicles may have a condition in which the incorrect thrust washer was installed in the transmission input carrier. Dealers are to replace the transmission.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| N232403290 | Service bulletin | Jun 29, 2023 | 10238342 | PDF, 102 KB |
What the document itself lists
The manufacturer titles it “N232403290 Service Update”.
Parts the bulletin names
| Part number | Description | Qty | Find it |
|---|---|---|---|
| 24045085 | Transmission | — | eBay Motors → |
| 19417577 | — | — | |
| 19418066 | — | — | |
| 84407373 | Exhaust System Front Gasket | — | eBay Motors → |
| 84308104 | Transfer Case Front Output Shaft Boot Clamp | — | eBay Motors → |
| 24245110 | Transfer Case Adapter Gasket | — | eBay Motors → |
| 23135703 | Transmission Fluid Cooler Pipe Seal | — | eBay Motors → |
Labour operation and the time the manufacturer allows
| Operation | Description | Time |
|---|---|---|
| 9106904 | Transmission Replacement 2WD 4WD | 5.6 hrs |
Read by machine from the document NHTSA serves (3 pages), read Sep 30, 2026. A part number is shown only where it matches GM’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote. Listings and prices on eBay Motors are the seller’s.
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The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themChevrolet 1 model year
GMC 1 model year
A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
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What owners reported
Source: NHTSA complaint databaseOwners of the 2 model years this bulletin names have filed 901 complaints with NHTSA since 2015. 200 of them name Power Train — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
I am writing to bring to your attention a recurring issue with my recently purchased 2023 Chevrolet Silverado, documented in detail here: . Despite the evidence presented in the document and my personal experience, Chevrolet claims there is no known issue with my vehicle.
2023 Chevrolet Silverado · Power Train · filed with NHTSA Dec 9, 2023 · ODI 11559244
In depth: 2023 Chevrolet Silverado transmission and drivetrain problems → · 2023 GMC Sierra transmission and drivetrain problems →
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the power train
Source: same model, same component group89 other manufacturer communications filed against these GM models under the same component group (power train), newest first. The eight newest are listed; the rest are on the Chevrolet list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| N252502891-01 | Service campaign | Aug 20, 2026 | Certain vehicles may have a condition in which the internal differential nut was cross threaded or missing during assembly. Dealers will rev… |
| N252517790 | Service campaign | Oct 14, 2025 | Certain vehicles, equipped with 8L80 or 8L90 Transmissions, may have a condition in which the reaction carrier cracks. Dealers are to replac… |
| N242454441 -03 | Service campaign | Oct 9, 2025 | Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure w… |
| 25-NA-080 | Service bulletin | Sep 4, 2025 | This service bulletin provides a procedure to overhaul the control valve to replace a plate and worn down check ball to correct the customer… |
| N252494003-01 | Service campaign | Jun 26, 2025 | Certain vehicles listed above, may have a condition where the connecting rod and/or crankshaft engine components in these vehicles may have… |
| N242483540-01 | Service campaign | May 21, 2025 | Certain vehicles listed above may have a condition in which the transmission may not shift properly. Dealers are to replace the transmission… |
| 22-NA-182 | Service bulletin | May 16, 2025 | This service bulletin advises the technician to check if the transmission cooler lines are twisted to correct customer concerns of Harsh Shi… |
| 24-NA-133 | Service bulletin | May 14, 2025 | This informational bulletin provides information on Wheel Drive Shaft Retention Snap Ring Design Change. |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Chevrolet and GMC, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM N232403290 a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the N232403290 repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way. Every GM warranty extension on file lists the ones GM has filed.
Which vehicles does N232403290 cover?
The manufacturer filed it against 2 model years across 2 brands (Chevrolet and GMC): 2023 Chevrolet Silverado, 2023 GMC Sierra. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.