GM bulletin 20-NA-136
What it saysThis informational bulletin describes/outlines the process for the 9T65 Automatic Transmission Replacement Pilot Program (U.S. NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Oct 24, 2024, received Aug 3, 2022, about the power train — 5 documents under this number. It names 36 model years across Chevrolet, GMC, Buick and Cadillac (2018–2025). 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 · Buick · Cadillac.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationWhat it applies to, as NHTSA’s summary states it — build dates and equipment as the manufacturer filed them. The dealer checks the VIN and the build date on the door jamb; a vehicle outside the window is not covered by this bulletin.
This informational bulletin describes/outlines the process for the 9T65 Automatic Transmission Replacement Pilot Program (U.S. Only).
Trouble codes it names: P0723 P0746 P0747 P0796 P0797 P187D P187E P18A8 P18AE P18E7 P18E8 P2724 P27F0 P2818 all 14 read from the document itself; NHTSA’s summary names none
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 20-NA-136 | Service bulletin | Oct 24, 2024 | 11010971 | PDF, 206 KB |
| 20-NA-136 | Service bulletin | May 3, 2024 | 11000362 | PDF, 231 KB |
| 20-NA-136 | Service bulletin | Aug 2, 2023 | 10241855 | PDF, 126 KB |
| 20-NA-136 | Service bulletin | Aug 4, 2022 | 10217851 | PDF, 105 KB |
| 20-NA-136 | Service bulletin | Jul 20, 2022 | 10217052 | PDF, 125 KB |
What the document itself lists
Labour operation and the time the manufacturer allows
| Operation | Description | Time |
|---|---|---|
| 8481048 | Perform Fluid Level and Oil Pressure Checks and Service Fast Learn | 1.5 hrs |
Read by machine from the document NHTSA serves (9 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.
Doing the repair yourself, or pricing it before the shop does? Search the part by fitment on eBay Motors — the listing and the price are the seller’s.
Find the automatic transmission for the 2025 Blazer →Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
Model years it names
Source: as the manufacturer filed themChevrolet 14 model years
Buick 5 model years
Cadillac 12 model years
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 36 model years this bulletin names have filed 3,142 complaints with NHTSA since 2015. 797 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.
On the 2018 Chevrolet Traverse, the 76 owners who gave an odometer reading for Power Train reported it at a median of 36,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
7-8 mild transmission slips/sticking 3 MAJOR transmission events where the car seized up completely and stopped running. Almost felt like a car crash. Very abrupt stop and almost caused people behind us to rear end us Car is only 21 months old / 17,000 miles. Most recent was in early August. We have not driven car since out of fear
2023 Chevrolet Traverse · Power Train · filed with NHTSA Sep 18, 2024 · ODI 11615200
The contact owns a 2023 Cadillac XT5. The contact stated that upon shifting into reverse(R), the vehicle intermittently failed to respond. The contact stated that the failure had progressively worsened, and the vehicle responded after an extended period. The vehicle was taken to the dealer; however, the failure was not duplicated.
2023 Cadillac XT5 · Power Train · filed with NHTSA Oct 5, 2026 · ODI 11769127
After waiting at stop light with foot on the brake (auto stop not engaged) the light turned green. After releasing brake pedal and the car rolling approx 1 foot , then starting to accelerate, within 1-1/2 seconds the transmission went into park abruptly. The shift lever displayed “Park” and “Parking brake” on the DIC illuminated.
2020 Buick Enclave · Power Train · filed with NHTSA Apr 21, 2024 · ODI 11584293
In depth: 2020 Chevrolet Blazer transmission and drivetrain problems → · 2019 Chevrolet Blazer transmission and drivetrain problems → · 2019 Chevrolet Traverse transmission and drivetrain problems → · 2018 Chevrolet Traverse 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 group59 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… |
| N252502890-01 | 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… |
| N242471460-01 | Service campaign | Aug 20, 2026 | Certain vehicles may have been built with an Electric Drive Unit mounting bolt that is too long, causing damage to the Drive Unit case. Deal… |
| 25-NA-001 | Service bulletin | Mar 13, 2025 | This service bulletin provides repair information to correct a customer concern of a transmission fluid leak. |
| 24-NA-232 | Service bulletin | Mar 7, 2025 | This technical bulletin provides repair information to correct a customer concern of Metallic Noise from Rear Differential on Acceleration. |
| PIP5981D | Service bulletin | Feb 26, 2025 | This Preliminary information communicates ordering process for the front and rear drive units are on restriction for all listed EV vehicles… |
| 16-NA-019 | Service bulletin | Feb 12, 2025 | This informational buleltin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flare… |
| 09-06-04-026Z | Service bulletin | Jan 9, 2025 | This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2. |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Chevrolet, GMC, Buick and Cadillac, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM 20-NA-136 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 20-NA-136 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 20-NA-136 cover?
The manufacturer filed it against 36 model years across 4 brands (Chevrolet, GMC, Buick and Cadillac): 2024 Buick Enclave, 2023 Buick Enclave, 2022 Buick Enclave, 2021 Buick Enclave, 2020 Buick Enclave, 2025 Cadillac XT5 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.