Jump to content

Recommended Posts

Posted

Truck is  2025 Chevrolet 2500 HD Custom 6.6 Gas . Truck was built in Oshawa .

I have a couple of threads on here fellas but I thought I would just check something out .

Someone has told me that there is a recall or a special bulletin for the tranny on this truck . Is this true ?

 

Also where do I look for recalls and Special Bulletins for this truck ?

Thank You !

 

Posted

Doubtful on a 24'+

Gm "upgraded" the valve bodies in late 23'iirc to the Gen 3 version. No recall on them,,, yet. 

 

I think Allison forcing Gm to not use their namesake after 26' will work in our favor. Hopefully, GM's hand will be forced to do a real, long term fix. 

  • Like 2
Posted

Thank You ! JW2024 and NoF-bdy Bs !

Posted
6 hours ago, No F-bdy Bs said:

Doubtful on a 24'+

Gm "upgraded" the valve bodies in late 23'iirc to the Gen 3 version. No recall on them,,, yet. 

 

I think Allison forcing Gm to not use their namesake after 26' will work in our favor. Hopefully, GM's hand will be forced to do a real, long term fix. 

Could you please explain the last sentence I'm not sure that I understand

Thank You 

  • 5 months later...
Posted

There is a TSB. 

 

https://static.nhtsa.gov/odi/tsbs/2025/MC-11014081-0001.pdf
 

My 24 3500 dually L8T with 28k on it had these symptoms so I dropped it off last week. Waiting on parts. It started while I was towing, tranny slipped and slammed into gear during a normal acceleration. I don’t pedal mash either, was towing about 10k at the time. It “slipped”, engine RPMs shot up and then it slammed into a low gear at about 40mph. From then on I was noticing odd downshifts and delayed engagement. 

  • 1 month later...
Posted

So I got my truck back 2 weeks ago. It was running fine, towed well on a trip up to the farm with 16k on an equipment trailer. Then, hours after towing, I went to get groceries and the transmission took a complete dump on me on the way home. Turned on to the road and it went into some super weird limp mode where it would only go about 10mph, was unresponsive to throttle input and would just randomly lurch forward. It was quite difficult getting it off the busy road. Tried disconnecting and reconnecting the battery to see if it was something dumb in the computer. It worked for about 100 feet and then went back into limp/lurch mode. So I had it towed to the dealer on the Sunday of Memorial Day weekend since I didnt want it sitting on the side of the road. Dealer got back to work today so it is in the hopper to get looked at.

 

My service advisor has been absolutely amazing through this process. The initial 3 weeks it was laid up really sucked since this is a commercial truck and our primary equipment hauler, but he really did his best to expedite the repairs. We will see what comes of this visit. I have no doubts that my dealer will be great, the shortfall will come with big GM who refuses to admit they have some sort of issue with this transmission. Just all TSBs with no increased parts support. 

Posted
On 5/26/2026 at 12:21 PM, stlchevy61 said:

So I got my truck back 2 weeks ago. It was running fine, towed well on a trip up to the farm with 16k on an equipment trailer. Then, hours after towing, I went to get groceries and the transmission took a complete dump on me on the way home. Turned on to the road and it went into some super weird limp mode where it would only go about 10mph, was unresponsive to throttle input and would just randomly lurch forward. It was quite difficult getting it off the busy road. Tried disconnecting and reconnecting the battery to see if it was something dumb in the computer. It worked for about 100 feet and then went back into limp/lurch mode. So I had it towed to the dealer on the Sunday of Memorial Day weekend since I didnt want it sitting on the side of the road. Dealer got back to work today so it is in the hopper to get looked at.

 

My service advisor has been absolutely amazing through this process. The initial 3 weeks it was laid up really sucked since this is a commercial truck and our primary equipment hauler, but he really did his best to expedite the repairs. We will see what comes of this visit. I have no doubts that my dealer will be great, the shortfall will come with big GM who refuses to admit they have some sort of issue with this transmission. Just all TSBs with no increased 

Following. I have 31K on my 2024 HD. The most I have towed so far is about 12K I have not had any transmission issues yet.

Posted

 

On 5/26/2026 at 2:21 PM, stlchevy61 said:

So I got my truck back 2 weeks ago. It was running fine, towed well on a trip up to the farm with 16k on an equipment trailer. Then, hours after towing, I went to get groceries and the transmission took a complete dump on me on the way home. Turned on to the road and it went into some super weird limp mode where it would only go about 10mph, was unresponsive to throttle input and would just randomly lurch forward. It was quite difficult getting it off the busy road. Tried disconnecting and reconnecting the battery to see if it was something dumb in the computer. It worked for about 100 feet and then went back into limp/lurch mode. So I had it towed to the dealer on the Sunday of Memorial Day weekend since I didnt want it sitting on the side of the road. Dealer got back to work today so it is in the hopper to get looked at.

 

My service advisor has been absolutely amazing through this process. The initial 3 weeks it was laid up really sucked since this is a commercial truck and our primary equipment hauler, but he really did his best to expedite the repairs. We will see what comes of this visit. I have no doubts that my dealer will be great, the shortfall will come with big GM who refuses to admit they have some sort of issue with this transmission. Just all TSBs with no increased parts support. 

Alright so this one ended up being a different TSB that was not related to the transmission at all. It was the O2 sensor wire that got too close to the exhaust and melted. I guess the 5v reference wire melted, shorted out and caused about 200 codes to populate and the truck to go into limp mode. 

 

https://static.nhtsa.gov/odi/tsbs/2024/MC-10253570-0001.pdf

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...