GM Finally Identifies 3.0 Duramax Thrust Bearing Build Dates in Updated Bulletin

October 14, 2026 | DuramaxNews.com

For more than a year, owners of the 3.0L Duramax LZ0 have been trying to determine which engines could be affected by the ongoing thrust bearing concerns.

Now, General Motors has finally provided something owners have been waiting for: specific build dates.

On October 13, 2026, GM revised Service Bulletin # 25-NA-307, identifying a vehicle build-date range of May 1 through September 1, 2025.

This is one of the most important updates to the bulletin since its original release in September 2025, and it could help owners better understand whether their trucks fall within the population GM is investigating.

GM Identifies May 1 Through September 1, 2025

The latest revision identifies the following vehicle build dates:

May 1, 2025 – September 1, 2025

The bulletin applies to certain 2025 and 2026 vehicles equipped with the 3.0L Duramax LZ0 engine, including:

• Chevrolet Silverado 1500

• Chevrolet Tahoe

• Chevrolet Suburban

• GMC Sierra 1500

• GMC Yukon models

  
  

Until this update, owners were largely left comparing reported failures, production information, and build dates themselves.

Some owners have questioned whether certain production periods were more susceptible to thrust bearing failures, while others have wondered whether the problem was isolated to a particular manufacturing batch.

GM has not provided that level of detail.

However, the addition of an official build-date range is a meaningful development.

It's important to understand that the dates published in the bulletin refer to vehicle build dates, not necessarily the date an individual engine was manufactured.

And while the dates establish the vehicles covered by this particular bulletin, they do not mean every engine built during that period will experience a failure.

What Is Happening Inside the Engine?

The concern centers around excessive crankshaft end play, potentially caused by a failure of the engine's thrust bearing.

The thrust bearing controls the crankshaft's forward and rearward movement inside the engine block.

A small amount of movement is normal, but excessive movement can indicate internal engine damage.

According to GM, owners may experience an unusual noise originating near the transmission bellhousing or an illuminated check engine light.

Technicians may also encounter the following diagnostic trouble codes:

• P06DD: Engine Oil Pressure Control Valve Performance

• P06DA-92: Engine Oil Pressure Control Valve Actuator

  
  

GM instructs technicians to inspect crankshaft end play when diagnosing the conditions described in the bulletin.

The published crankshaft axial clearance specification for the LZ0 is 0.0033–0.0124 inches (0.084–0.316 mm).

To perform the inspection, technicians access the torque converter through the transmission housing opening and use a dial indicator positioned against the crankshaft pulley bolt to measure movement.

GM specifically cautions that flexplate movement can make the torque converter appear to move farther than the crankshaft itself.

GM Also Adds a Mileage Limitation

Along with the new build dates, GM added another statement to the bulletin:

"This bulletin does not apply to vehicles with more than 20,000 miles."

This is an interesting addition because it establishes a mileage boundary for this specific diagnostic procedure.

It also raises questions about how long an engine could operate before excessive crankshaft end play becomes apparent.

An engine operating normally during its first several thousand miles is certainly encouraging, but it doesn't necessarily rule out a problem developing later.

GM has not explained why 20,000 miles was selected, and the bulletin does not establish a specific mileage at which thrust bearing failures typically occur.

Importantly, this limitation does not mean thrust bearing failures cannot occur beyond 20,000 miles, nor does it automatically exclude those vehicles from applicable powertrain warranty coverage.

Engine Replacement Remains the Required Repair

If excessive crankshaft end play is confirmed, GM continues to instruct dealerships to replace the complete engine assembly.

But the repair doesn't stop there.

The bulletin also calls for replacement of the turbocharger and turbocharger oil feed pipe.

These additional components are particularly interesting because a thrust bearing failure can introduce metallic debris into the engine's lubrication system, potentially contaminating other oil-fed components.

GM does not specifically identify the reasoning behind every component replacement in the bulletin, but the repair procedure makes it clear that this is more extensive than simply replacing a damaged bearing.

Does This Mean Trucks Outside These Dates Are Safe?

Not necessarily.

The newly identified build-date range establishes which vehicles GM has included in this bulletin. It does not prove that engines manufactured or installed outside this period are immune to thrust bearing problems.

Likewise, an engine inside the specified date range is not automatically defective.

GM has not published an overall failure rate, identified the number of potentially affected vehicles, or announced a recall associated with this bulletin.

Those distinctions matter, particularly when owners are trying to determine whether their trucks may be affected.

The Information Owners Have Been Waiting For

Since the original release of Bulletin # 25-NA-307 on September 30, 2025, GM has made numerous revisions involving diagnostic procedures, replacement parts, and warranty information.

The October 13, 2026 update is different.

For the first time, GM has provided a specific vehicle build-date range for this thrust bearing bulletin.

That gives owners and technicians a much clearer reference point when evaluating reported failures and comparing production information.

There are still unanswered questions, particularly concerning the underlying cause, how widespread the problem may be, and whether additional production periods could be involved.

But identifying the May 1 through September 1, 2025 build window is a significant step toward understanding the issue.

Now we'd like to hear from 3.0 Duramax owners.

If you own a 2025 or 2026 Silverado, Sierra, Tahoe, Suburban, or Yukon equipped with the LZ0, check your vehicle's build date.

Does your truck fall within the newly identified window? How many miles have you accumulated, and have you experienced any unusual engine noises or thrust bearing concerns?

Share your experience in the comments.

Source: General Motors Service Bulletin #25-NA-307, Version 9, revised October 13, 2026.