Engine Break-In confusion

[Steve Karolek]

OK, I just finished reading the owner's manual, cover to cover, minus the sections that don't apply. I'm a bit confused by what I see as a contradiction regarding break-in...

Page 228 says: The Cummins Turbo Diesel engine does not require a break-in period due to its construction. Normal operation is allowed, provided the following recommendations are followed (list of common sense stuff).

Page 229 says: Light duty operation such as light trailer towing or no load operation will extend the time before the engine is at full efficiency. Reduced fuel economy and power may be seen at this time.

Implication: No need to baby this beast, put it to work immediately.

Page 229 continues: Because of the construction of the Cummins Turbo Diesel engine, engine run-in is enhanced by loaded operating conditions which allow the engine parts to achieve final finish and fit during the first 6000 miles.

I get it: put it to work right away.

Page 323 says: Caution! Do not tow a trailer at all during the first 500 miles the new vehicle is driven. The engine, axle or other parts could be damaged.

Wait, didn't pages 228 and 229 say put the truck to work immediately and work it hard to finish the engine?

Page 323 continues: Then, during the first 500 miles that a trailer is towed, do not drive over 50 mph and do not make starts at full throttle. This helps the engine and other parts of the vehicle wear in at the heavier loads.

So... no towing for 500 miles THEN work it to break it in but not too hard for another 500 miles then harder for another 5000 before the engine is "finished"?

Or... ignore page 323, drive it like a truck per pages 228/229?

Thanks... this is the last time I'm a "first time diesel driver"

Steve

 

[stevenP]

I have two of these CTD trucks. Both bought new. Dont loose a lot of sleep over nothing. Just drive the truck, and enjoy. I did go out of my way to just drive the dually , for a 1000 miles before I did any heavy towing. But then I have seen threads on here where guys didnt. I think its more about breaking in your drive line components rather than the engine itself. My main use is for towing a large fifth wheel RV.

 

[Steve Karolek]

@stevenP right now, my main use of the truck is dreaming of when my large 5th wheel (Grand Design Momentum 397th) will be delivered in May-ish. That said, I'm going to drive it to MN today to visit our grandson for the weekend (kids going to FL, Grandparents get to spoil the little one). That'll take care of about 500 miles...

 

[litzdog911]

I also noticed those seeming contradictions in the Owners Manual. My new 2020 2500 is due at the end of this month and I can pick up our new travel trailer anytime, so I'm also wondering about just how much "break-in" my truck will need before towing.

 

[Jimmy07]

OK, I just finished reading the owner's manual, cover to cover, minus the sections that don't apply. I'm a bit confused by what I see as a contradiction regarding break-in...

Page 228 says: The Cummins Turbo Diesel engine does not require a break-in period due to its construction. Normal operation is allowed, provided the following recommendations are followed (list of common sense stuff).

Page 229 says: Light duty operation such as light trailer towing or no load operation will extend the time before the engine is at full efficiency. Reduced fuel economy and power may be seen at this time.

Implication: No need to baby this beast, put it to work immediately.

Page 229 continues: Because of the construction of the Cummins Turbo Diesel engine, engine run-in is enhanced by loaded operating conditions which allow the engine parts to achieve final finish and fit during the first 6000 miles.

I get it: put it to work right away.

Page 323 says: Caution! Do not tow a trailer at all during the first 500 miles the new vehicle is driven. The engine, axle or other parts could be damaged.

Wait, didn't pages 228 and 229 say put the truck to work immediately and work it hard to finish the engine?

Page 323 continues: Then, during the first 500 miles that a trailer is towed, do not drive over 50 mph and do not make starts at full throttle. This helps the engine and other parts of the vehicle wear in at the heavier loads.

So... no towing for 500 miles THEN work it to break it in but not too hard for another 500 miles then harder for another 5000 before the engine is "finished"?

Or... ignore page 323, drive it like a truck per pages 228/229?

Thanks... this is the last time I'm a "first time diesel driver"

Steve

Page 323 only has to do with rear end gears break-in. So...drive it how you want, just stay under 50mph when towing something for the first 500 miles, which is standard procedure for any new gear break-in.

 

[Halligan]

Page 323 only has to do with rear end gears break-in. So...drive it how you want, just stay under 50mph when towing something for the first 500 miles, which is standard procedure for any new gear break-in.

^^^This^^^ It's all about the gears wearing in during the first 500 miles. Dump that diff oil at about 1000 miles. The oil will be nasty from the gear wear in. Refill diff with some good quality gear oil then tow the heaviest thing you can find to break that Cummins in proper.

 

[Steve Karolek]

Makes sense, thanks!

Sent from my Pixel 3 XL using Tapatalk

 

[stevenP]

I have been meaning to check the diffs, just never did. But my dually only has 17K on it at the moment. Most of that was pulling this. I had a duramax sliverado before this, and the ram definitely pulls harder. Best feature by far is the exhaust braking, man does that really make a huge difference.

 

[Blazin383]

I had the same questions when reading my owners manual. I put about 350 miles on my 19 3500 HO 6.7 before hooking up my 20' 2900# cargo trailer, loading a cord of fire wood in it and towing it the 30 miles home at highway speeds. I towed it in Tow/Haul mode and figured the load was light enough to not put much of a strain on the big girl and unlikely to hurt anything. I hope I was right!

 

[Steve Karolek]

I put 750 "no load" highway miles on the truck last weekend... made arrangements to borrow one of the equipment trailers from the scout troop my son was a member of for my initial lower speed towing break in miles. No idea if I'll get 500 before I want to hook a camper up in Mid April, but hope so, because driving across the country at 50mph towing break in will drive me nuts

 

[Steve Karolek]

After a few COVID related delays, I finally logged my first 50 "loaded" break-in miles. New Grand Design Momentum 397TH toy hauler. My wife in the "pilot car" behind me had to remind me a few times to stick to break-in speed limit. Another 150 coming up this weekend on our first "close to home" camping trip. After tent camping for 50+ years, this is going to be a different experience!

 

[Albert525]

^^^This^^^ It's all about the gears wearing in during the first 500 miles. Dump that diff oil at about 1000 miles. The oil will be nasty from the gear wear in. Refill diff with some good quality gear oil then tow the heaviest thing you can find to break that Cummins in proper.

I find many saying is the diff more than engine. So many say different things, default.
with the cars its the diff as well mainly
honestly I drive city babying it initially for at least 50 miles, then easy city. Most manuals say wot after 50 or so, but break in for diff is 500. Varying speed is good, why I do city miles for a wile.

 

[Elkman]

The engine bearing need to seat properly and this is why they advise not putting the engine under a heavy load for the first 500 miles. This is really common sense and has been recommended for every truck I have bought in the past 50 years.

Most manufacturers also recommend not staying at a constant speed during this period so no using cruise control and running at 65 mph the entire time. This also makes sense in terms of the engine break-in.

I would also change the transmission filter after 500 miles for any truck with an external trans filter.

But cudos for reading the manual. Next step is to put together a maintenance schedule and log for the truck.