2020 Silverado 3500HD Duramax Diesel "Allison" transmission rear wheel lock-up lawsuit

RB Patterson · April 28

Rear wheels lock up when it tries to downshift while towing (going uphill with our 5th-wheel RV). This is the known problem that 463,000 trucks were recalled and programed to try and let the owner know about 10,000 miles before a lock-up happens (feels like you ran over a telephone pole). Ours just happens to be one of the "lucky" ones that locks up without prior warning. We took it into nearest Chevy dealer (out in CA). After 2 weeks waiting, we were told by the dealer they didn't need to do anything relating to the recall because it wasn't throwing the PO747 error code. I offered to take a technician up a hill on the highway with our 13,000 lbs 5th-wheel in tow, but they declined. They asked us to wait in California (2100 miles from our home) for another 8 weeks for a GM engineer to come to the dealership and look at it. We declined and put our camper in storage and drove the truck home to be serviced local. We can't wait the 8-10 weeks for a GM engineer. Does anyone know who to contact at GM to get our costs covered? (note: We have filed reports with NHTSA and opened a file with the GM Customer Care line- Who told us we were covered by the recall, but because they were not part of the GM technical service (TAC), they had no authorization to tell the dealer what to do as dealers are independently owned.) Are we forced into a lawsuit to recover our repair costs and expenses for what should be a warranty repair?

And imagine our surprise when we learned that despite the branding on the hood, we didn't have an Allison transmission.

Reference: Special Coverage N242454441-03

DenaliHD23 · April 28

Hi RB,

I sympathize with your dilemma ~ we have a 23 3500HD with a 6.6 / 'Allison'. I have been a mechanic for 51 years (retired now) and have been a GM guy for many years. I'm just waiting for the dreaded incident to happen while towing our 10K trailer. We have 20,000 on our rig and this situation is inexcusable. Flashing your TCU to warn you ahead of time is bogus. Ford pulled that crap on their Triton V-8s while I was a fleet district mechanic. After that didn't work (recall) they forced us to replace spark plugs and charged per hour for those that broke off in the head. All on trucks that 'should have been ' under emission warranty but weren't because they were over 8600 GVW. Still a F-250!

I have been weighing purchasing the upgraded valve body from Next Gen Drivetrain and installing it, just to avoid grenading the rest of the transmission and drive train ~ not to mention the possibility of a major wreck. The other option is to buy their valve body upgrade kit and install yourself if capable.

Down the line, I would hope there would be a refund for the purchase / repair costs. The understanding is that GM purportedly does not have the parts to repair the defective units. This whole thing is a major malfunction.

Oh ~ for shares the same transmission (it was a joint venture with GM ~ they just paid to use the name 'Allison') Fords don't seem to suffer the issue as they don't have the crappy valve body in them.

I wish you the very best in your journey. I think we all have a fight ahead of us to get this rectified.

Greg

RB Patterson · April 29

17 hours ago, DenaliHD23 said:

Hi RB,

I sympathize with your dilemma ~ we have a 23 3500HD with a 6.6 / 'Allison'. I have been a mechanic for 51 years (retired now) and have been a GM guy for many years. I'm just waiting for the dreaded incident to happen while towing our 10K trailer. We have 20,000 on our rig and this situation is inexcusable. Flashing your TCU to warn you ahead of time is bogus. Ford pulled that crap on their Triton V-8s while I was a fleet district mechanic. After that didn't work (recall) they forced us to replace spark plugs and charged per hour for those that broke off in the head. All on trucks that 'should have been ' under emission warranty but weren't because they were over 8600 GVW. Still a F-250!

I have been weighing purchasing the upgraded valve body from Next Gen Drivetrain and installing it, just to avoid grenading the rest of the transmission and drive train ~ not to mention the possibility of a major wreck. The other option is to buy their valve body upgrade kit and install yourself if capable.

Down the line, I would hope there would be a refund for the purchase / repair costs. The understanding is that GM purportedly does not have the parts to repair the defective units. This whole thing is a major malfunction.

Oh ~ for shares the same transmission (it was a joint venture with GM ~ they just paid to use the name 'Allison') Fords don't seem to suffer the issue as they don't have the crappy valve body in them.

I wish you the very best in your journey. I think we all have a fight ahead of us to get this rectified.

Greg

Thanks for the response Greg. We had looked at the Next Gen Drivetrain products and when this GM repair fails, we will be looking at going that route. Just a question: why would you do the Pulse delete option? (I watched the install video and it really didn't cover the advantage/reason for doing this option)