2020 GMC 3500 Duramax Allison 10 speed failure with 13,500 miles on it

Richard Helm · August 26, 2022

I have 13,500 miles on my 2020 Duramax 3500 towing a fifth wheel with a max gross of 16,000 pounds about 1/4 of those miles, and the transmission started making a gear noise. The dealer is telling me that all of my clutches are burned up and my torque converter is bad. I would like them to swap out the transmission with a new one but they are saying no. In addition the parts are backordered. Has anyone had a problem like this, and have you been able to get a new transmission? I don't want a rebuilt transmission on my new truck.

CamGTP · August 27, 2022

Probably pretty slim to find people on here with that exact failure but you are at the mercy of the warranty and what GM will do to fix it.

If they say you will not get a new transmission, then you aren't getting one. GM rarely changes their mind when it comes to warranty repairs and what they will cover. Rebuilding the transmission is cheaper for them and because you didn't grenade the insides and break a bunch of hard parts, they will just do a repair on it.

Technically it's not new anymore, you are already 3 model years old to them and they don't care.

newdude · August 27, 2022

16 hours ago, Richard Helm said:

I have 13,500 miles on my 2020 Duramax 3500 towing a fifth wheel with a max gross of 16,000 pounds about 1/4 of those miles, and the transmission started making a gear noise. The dealer is telling me that all of my clutches are burned up and my torque converter is bad. I would like them to swap out the transmission with a new one but they are saying no. In addition the parts are backordered. Has anyone had a problem like this, and have you been able to get a new transmission? I don't want a rebuilt transmission on my new truck.

So when it comes to GM (and I'm sure other automakers) for warranty repairs on major components (engines, transmissions, transfer cases) here's what happens.

Dealer is required to tear down the transmission to find the root causes/issues of failure. They are then supposed to do a cost comparison worksheet to determine what is the more warranty cost effective route of repair. If they can install new parts into your transmission to fix it (clutches, converter, etc.) and the cost to do such is less than the cost of replacing the entire transmission, then GM will approve the repair rather than the replacement.

If it costs more to overhaul your transmission than replacing it, then GM will approve the replacement assembly instead. Customer has no control over this aspect technically, its all GM's policy and procedure.

Where this gets interesting in your case is that GM has all 4 p/ns of transmission assemblies in stock at their various PDC (parts distribution centers) so your dealer can get a transmission faster as they aren't on backorder.

The only way GM will put a transmission in your truck under warranty is two reasons that I can think of. One that will likely for sure work is if you pay out of pocket the difference in the cost comparisons. So say its $4000 to repair yours, and it was $5500 to replace it, if you volunteered to pay that difference you can have a transmission put in it.

The other option would be to try and call customer assistance, give them the details on your truck and see if GM would be willing to help you out as a transmission would have you on the road faster than waiting for backordered parts and see if they can do anything about this for "customer satisfaction." You could also try with your dealer to see if they can get their dealer rep involved and they can tell him/her "look, customer is upset, GM has transmissions in stock, is there anything we can do?" We had a situation like this with a Camaro V6 customer with his engine. GM ended up putting an engine in however the customer did agree to pay the difference to do so.

Just don't be a raging a-hole in your approach. Be professionally upset. Being an a-hole will get you put on the backburner.

Edited August 27, 2022 by newdude

calgator73 · August 27, 2022

18 hours ago, Richard Helm said:

I have 13,500 miles on my 2020 Duramax 3500 towing a fifth wheel with a max gross of 16,000 pounds about 1/4 of those miles, and the transmission started making a gear noise. The dealer is telling me that all of my clutches are burned up and my torque converter is bad. I would like them to swap out the transmission with a new one but they are saying no. In addition the parts are backordered. Has anyone had a problem like this, and have you been able to get a new transmission? I don't want a rebuilt transmission on my new truck.

GM doesn't seem to mind paying for a rental vehicle for a month while waiting on backorder bolts. Crazy. Maybe use your intended use of the vehicle to get them to authorize an HD truck from enterprise truck rental?

Richard Helm · August 30, 2022

When I told the dealer I wanted a new transmission, the service manager told me that GM doesn't like to give those away, and that they are really expensive. I told him no kidding, I'm still paying for my broken one. How do you say something like that to a customer?

I created a case #, last week, with GMC. I told them I wanted a new transmission, and the reasons why. They said they would call me back, but have not done so yet. I requested a rental from the dealer and they said they would look into it, but that they were very busy. Again, with great customer service.

Richard Helm · August 30, 2022

The dealer just got back to me and GMC will give them $44 a day for a rental, he said "you get what you get", meaning whatever $44 per day will get you. If you have a business that requires a truck, you are out of luck. They have had it for almost a month now.

Richard Helm · August 31, 2022

Great news! The dealer called me and they are putting in a new transmission. The Dealer and GMC came through. I am very happy. I love the truck but was disappointed with the thought of having a rebuilt transmission.

Mechanical things can break. No matter how good they are, they are still machines, built by people, and they are not immune. How a company takes care of their customer when something does happen means everything. I don't think I can ask for more.

They are saying I should have my truck back by Friday.