hey all I just bought a 05 3/4 ton cummins . I just wanted to know if there was a sugested break in period that I should follow as I have never bought new before. I would like to hear it from a fellow cummins fan rather than my meatball car salesman who didnt know diesels dont have spark plugs . If im correct cant you drive them like you stole them right off the bat?

thanks...

 

According to Cummins.com and your owners manual, the engine comes from the factory ready to be worked. Keep your fluids topped off. Use petroleum based oils for the first two changes. Vary your speed and work the engine.

If you have the AAM axles (I don't recall DC changing them since 02 or 03), NO TOWING for the first 500 miles. After that, no towing ABOVE 50 MPH for the next 500 miles. HTH

 

Read the owners manual.Differantials need break in more then engine.

 

Read the owners manual
You will be amazed at what sort of information is in there that you can actually use

Seriously, though, as others have said, just drive it resonably for the first 500 and no towing also.
Then " Drive It Like You Stole IT"

 

Also the WARRANTY info.

 

alrighty thanks for the info guys. I really appreciate it.

C'mon grown men dont read instructions or owners manuals . . .

 

Break in period is more for the diff's and trans than for the engine. Once your past 500 miles, work her like she's going out of style!!!! That's how they're made!!! They'll be better to you if you work them hard rather than baby them!! Working hard=towing and hauling heavy loads for extended miles!!

 

(Spoken in harsh Mexican voice) Manual....We don need no stinkin manual !!

 

I thought break in on a cummins is 150k or just starting to break in? I myself decided not to wait that long.
Drive of the lot like you stole it will make engine loosen up alot better and not so tight!

 

get the engine up to temprature then load the snot [full load] out of it for about 30 min and your engine is pretty much broken in at that point... that isn't good for the trans and diff's so what i did was to drive in circles and in city for the first hour of ownership then WOT pulls in 4-5-6 gears from about 1400rpm and up to governor... don't be afraid to drive the engine HARD... if you baby it around, well, you will take that 30,000 miles to break the engine in [if it ever does break in properly at all]...

sorta on topic, but for the OTR truck engines, after an engine overhaul [inframe], if you can't prove you loaded the engine to break it in properly, you may be denied warrenty by the manufacture...

 

This may sound silly but what how will i know if my engine is broken in properly nickleinonen??

 

500 miles before towing (for rear diff) then load her up with a load. Suggested is to pull a car trailer or something heavy. Not sure where I read it but it did say that if you don't tow or haul anything, it could be close to 25,000 miles before motor is considered broken-in.

So go tow something.

How to tell? Slightly better fuel mileage I hear.

 

Sounds good, we have an old rawhide 2 place horsetrailer that we tow frequently. Ill put her on the the new truck after 500 miles. Im not sure what the trailer weight is because it belongs to my father. But a couple of horses and the old iron trailer will do just fine im thinking..

 

hello,

i am pulling an airstream trailer that weighs in at about 4,500 lbs. i did not tow for the first 500 miles then kept in under 50 for 500 miles of towning while adjusting my speed. i have about 6675 miles on the truck now of which 4000 is towning my trailer. how long before the motor should be broke in? i have about another 4,000 to tow the airstream before returning to socal.

thanks,
david out of socal, now sitting in flint, michigan

 

Owner's maunal? you mean my truck has one? Where would I find it?