3.0L Duramax Break In

[TheDadMan]

I am buying a 2021 AT4 next week with the 3.0/10 speed powertrain.  I have owned a 6.6 LBZ Duramax in the past so not a diesel newby.  I am driving 250 miles to an out of state dealership to get this truck.  My question is:  what advice can you provide on the proper break in procedure for this powertrain?  The first miles on this truck will be 250 miles of interstate driving from Pocatello ID to Butte MT.  I plan to use the truck to tow my camper this summer so I need to get it broke in for trailer towing pretty quick.  Any thoughts will be appreciated.  Thanks

[Grumpy Bear]

14 minutes ago, TheDadMan said:

I am buying a 2021 AT4 next week with the 3.0/10 speed powertrain.  I have owned a 6.6 LBZ Duramax in the past so not a diesel newby.  I am driving 250 miles to an out of state dealership to get this truck.  My question is:  what advice can you provide on the proper break in procedure for this powertrain?  The first miles on this truck will be 250 miles of interstate driving from Pocatello ID to Butte MT.  I plan to use the truck to tow my camper this summer so I need to get it broke in for trailer towing pretty quick.  Any thoughts will be appreciated.  Thanks

 

Saw your post 16 hours ago. See your not getting any help here.

Could it be you've already told everyone what you are going to do? 

[btj_z71]

19 minutes ago, TheDadMan said:

I am buying a 2021 AT4 next week with the 3.0/10 speed powertrain.  I have owned a 6.6 LBZ Duramax in the past so not a diesel newby.  I am driving 250 miles to an out of state dealership to get this truck.  My question is:  what advice can you provide on the proper break in procedure for this powertrain?  The first miles on this truck will be 250 miles of interstate driving from Pocatello ID to Butte MT.  I plan to use the truck to tow my camper this summer so I need to get it broke in for trailer towing pretty quick.  Any thoughts will be appreciated.  Thanks

There isna break-in period listed in the diesel supplement that you'll get when you pickup the truck.  I can't remember it off the top of my head but it'll be in that book when you get the truck.

[redwngr]

You'll get lots of opinions.

 

Mine is that variation is the key.

Different speeds, different acceleration rates.

 

Don't forget the process is also for the rest of the powertrain, including the brakes.

 

3.0L Diesel OM supplement doesn't add anything to the regular OM regarding break-in.

 

OM says:

 

 The vehicle does not need an elaborate break-in. But it will perform better in the long run if you follow these guidelines:
. Keep the vehicle speed at 88 km/h (55 mph) or less for the first 805 km (500 mi).

 

. Do not drive at any one constant speed, fast or slow, for the first 805 km (500 mi). Do not make full-throttle starts. Avoid downshifting to brake or slow the vehicle.

. Avoid making hard stops for the first 322 km (200 mi) or so.

During this time the new brake linings are not yet broken in.

Hard stops with new linings can mean premature wear and earlier replacement.

Follow this breaking-in guideline every time you get new brake linings.

 

. Do not tow a trailer during break-in.
See Trailer Towing 0 291 for the trailer towing capabilities of the vehicle and more information.

 

Following break-in, engine speed and load can be gradually increased. 

 

 

Both manuals can be downloaded from GM's website if you want an electronic copy.

[SVG]

I drove mine back to Montana from Coeur d'Alene on I90. Did over 55 mph but didn't really load the engine, especially coming over the pass. Smooth and gradual acceleration. Tried to vary speed as much as the conditions allowed.

 

I'll bet your going to be extremely pleased with the new truck. I know I am.

[TheDadMan]

Being new to this forum I can’t figure out how to reply to each individual post so I will just say THANKS for the advice.  I appreciate hearing from experienced car guys

[Firehawk99]

My 2020 trail boss had some major electrical issues 2 weeks before my family and I were going on vacation. They couldnt get it fixed in time so they made me an offer I couldnt refuse on a 21 TB with a 6.2. They gave me 1,000 more than i paid for it 8 months prior. I left for a 1,500 mile trip one way with 30 miles on it. What i did was use thd manual shift mode and varied engine rpm's every 15 min. And didnt hammer down until it had about 700 miles on her. I changed the oil when we got to our destination.

[Duxtom]

On 5/6/2021 at 12:58 PM, SVG said:

I drove mine back to Montana from Coeur d'Alene on I90. Did over 55 mph but didn't really load the engine, especially coming over the pass. Smooth and gradual acceleration. Tried to vary speed as much as the conditions allowed.

 

I'll bet your going to be extremely pleased with the new truck. I know I am.

Hello,

 

Doing this exact same trip next week in a 2024 3.0L… how did this work out for you in the long run? Do anything differently if you were going to do it again tomorrow? Thanks!

[SVG]

Worked out great. I'd do the same thing again without hesitation.