I have about 3500 miles on my truck now and have towed some light loads (~7000lb travel trailer max). Next week I may need to pull a 12-13k pound gooseneck with a tractor a few hundred miles. Does my truck (particularily the engine and trans) have enough mileage to be broken in enough to safely pull that trailer? This is my first brand new truck so this break in business is all new to me. I am dying to pull the trailer to see how it stacks up to my fathers 2000 7.3.

Yes, you'll be fine. :)

I believe the 3500 Miles is Perfect, and Time for the Heavy load to finish breaking her in MYself...

I would have hooked to the heavier trailer around 1500 I believe if you baby the truck it will not be as good a tow rig,remember the tranny is learning also,so you should drive it like your gonna drive it every day,so the tranny knows what to expect :~)

Drive that Thing Dude LOL

I broke my truck in for 500 miles (per GM) then went straight to heavy towing. That was about 90K ago. I wouldn't worry about a thing. Diesels love to work. Just don't forget to change your diff oil if you haven't already. There is a break in period for the G80 Locker but once you drain the initial oil you can easilly go 100K between changes.

After day 1 of the trip, I am 100% impressed. This truck pulls that 12k lb trailer like my old truck pulled the little 6-7k travel trailer. The exhaust brake, torque, and quietness of this truck make it amazing

After day 1 of the trip, I am 100% impressed. This truck pulls that 12k lb trailer like my old truck pulled the little 6-7k travel trailer. The exhaust brake, torque, and quietness of this truck make it amazing

I completely agree! FYI, I hooked up to my 30' enclosed trailer with 550 miles on the clock. I gave it the recommended 500-mile break-in per the manual and immediately started using it like I will the entire time I own it. I'm really enjoying the quietness with the power. I guess at 33 I'm officially old. ;)

Yes, I too followed the Owners Manual recommendation - no towing for 500 miles.

How to break in a diesel engine:
http://www.thedieselstop.com/contents/getitems.php3?Breaking%20in%20a%20Diesel%20Engine

;)

How to break in a diesel engine:
http://www.thedieselstop.com/contents/getitems.php3?Breaking%20in%20a%20Diesel%20Engine

;)


Recently purchased a 2010 MINI Cooper and it's break-in recommendations are for 1,200 miles. It even mentions that your tires need several hundred miles to break-in. Avoid full throttle and use of the transmission kick-down mode. Vary speeds and keep below 4,500 RPM and 100 MPH. (Speed limiter a bit higher on a MINI than a Duramax at 125 MPH - Most def have had the MINI going faster than the Duramax already). :D

I would say that is closer to what most of us would do with a Duramax. Since Dave Smith was far from home I headed right out on a 350 mile drive at 70 MPH, no cruise control per the dealer's recommendation. I did do the 1,000 mile first tow by chance, right before I ever say that Ford article. I have seen slight but steady MPG gains over 40K+ miles and use no oil to speak of when not towing. The transmission and differentials make no noise. Must have done something right.

Now the MINI turbo charged engine oil is down half a quart at 2,500 miles. Hopefully that subsides after a few more miles, but these little turbo engines are known for using oil. Interestingly the MINI hits peak torque at 1,600 RPM same as the Duramax. 1.6 L / 97 C.I. / 172 HP / Peak Torque @ 1,600-5,000 RPM (OHC, 16 Valve)....... In a car that weighs less than 3,000 lbs - she really scoots. Switched to Michelin Primacy MXV4 low rolling resistance tires and got 36.5 MPG first trip. Sweet.

:cool:

My preference is always to put a nice stout load on the engine just as soon as possible. With a new truck this would be after 2 or 3 short trips to let the ring and pinion gears seat in. Say 100-200 miles in 3-4 trips and no high speeds then drop the oil and filter and go right to Delvac 1 synthetic at this point.

Cylinder pressure seats rings and enhances the break in process.

My preference is always to put a nice stout load on the engine just as soon as possible. With a new truck this would be after 2 or 3 short trips to let the ring and pinion gears seat in. Say 100-200 miles in 3-4 trips and no high speeds then drop the oil and filter and go right to Delvac 1 synthetic at this point.

Cylinder pressure seats rings and enhances the break in process.


The statement, "Cylinder pressure seats rings and enhances the break in process" is the exact opposite of the truth. Adding the higher combustion temperatures of towing to the high friction condition that exist between rings in cyclinder walls prior to break in can ruin compression rings. Specifically, they can hit their transfer temperature. This is the reasoning behind the owner's manual warning not to tow any thing heavy for the first 500 miles.

I get a kick out of people that think they know more than the manufacturer. Just follow the manual. Take it easy for 500 miles, change the oil if it makes you feel better, and then let her rip.

I get a kick out of people that think they know more than the manufacturer. Just follow the manual. Take it easy for 500 miles, change the oil if it makes you feel better, and then let her rip.
x2

You get a different answer everytime you ask someone. The manual said to not tow and to vary RPM's for the 1st 500 miles, and that's what I did. I hooked up to my 30' enclosed trailer at 550 miles for about 50 miles of pulling. The oil used during break-in is very important, too, but that's a completely different discussion. ;)

The statement, "Cylinder pressure seats rings and enhances the break in process" is the exact opposite of the truth. Adding the higher combustion temperatures of towing to the high friction condition that exist between rings in cyclinder walls prior to break in can ruin compression rings. Specifically, they can hit their transfer temperature. This is the reasoning behind the owner's manual warning not to tow any thing heavy for the first 500 miles.

Did you know that EVERY Duramax engine is test run on a dyno before shipping? I believe it is a 15 minute cycle with the first few minutes used to "shake down and then the following period is at FULL RATED POWER.

Yes we toured the facility back in 2002 I believe it was.

Mine have all been run this way including my latest built engine. Roll in, make pressure, roll out let the ensuing debris wash out. Many Farmers learned the hard way the perils of running a fresh tractor engine on "shit spreader duty" and having glazed cylinder walls...

The 500 mile statement is to ensure that the ring and pinion do not get too hot during their break in.


All Kennedy Diesel built engines are recommended to be run in assertively on a dyno as early as possible in their life...

run them nice the first 500 miles, then drive like you are going to use. Has worked for me for the last 30 odd trucks, 9 of them Duramax's. The sooner you break them in the sooner your milage improves. Change the diff fluid at 500 miles, change the oil at 2k and go :)

My preference is always to put a nice stout load on the engine just as soon as possible. With a new truck this would be after 2 or 3 short trips to let the ring and pinion gears seat in. Say 100-200 miles in 3-4 trips and no high speeds then drop the oil and filter and go right to Delvac 1 synthetic at this point.

Cylinder pressure seats rings and enhances the break in process.

John,
What do you consider a nice stout load? Surely our 14K 5th would be a bit much----or not?
Interesting your thoughts on the ring and pinion; I have always thought it took around 500 miles so that is when I always change the pumpkin oil. If what you say is indeed correct then I'm leaving trash in there far too long; thoughts?
So far what are your respected thoughts on the whole LML package? I think it's time to replace the LBZ but thus far am a long way from being convinced enough to make the jump.

Randy Moss

John,
What do you consider a nice stout load? Surely our 14K 5th would be a bit much----or not?
Interesting your thoughts on the ring and pinion; I have always thought it took around 500 miles so that is when I always change the pumpkin oil. If what you say is indeed correct then I'm leaving trash in there far too long; thoughts?
So far what are your respected thoughts on the whole LML package? I think it's time to replace the LBZ but thus far am a long way from being convinced enough to make the jump.

Randy Moss

Randy,

That's plenty of load. Maybe a bit much depending on conditions. Just take it easy and roll in and out without kicking down. This is tough for many as they face a lot of traffic. Here I have a 20 mile block that we run as a tow test when customers come in for tuning. It has a few short but steep grades and traffic is genetrally minimal. I also like to have a VERY good oil in place for this. The whole break in thing was discussed MANY years ago on the original GM Diesel Forum (The Diesel Page) when the Dmax was in it's infancy and those "in the know" agreed. All three of my trucks were broken in aggressively once the R&P were in the clear. There is a recommended break in from Eaton (not sure about AAM) regarding rear diffs, ring and pinions, etc and this was posted and discussed. The idea is that there is significant heat generated as they wear in and too much heat can soften the gears so short trips with ample cool down are recommended initially. To be honest, my 2005 and 2007 still have the original diff lube in them.

I'll have to sell or trade one to make room for the LML. Elaine won't let me have four Dmax trucks. I'm anxious to get ahold of one. Thinking the 05 (my keeper truck) will be the one that gets replaced and the 2007 (puddle jumper) will stick around a bit until the next short term opportunity arises.

For point of reference, the built 7.1 stroker in my 2002 was run in the driveway briefly to check for leaks and then we took it to town and then another 6 miles to grocery store. On this trip I rolled into it a couple of times making about 20psi boost at light throttle and then backed off to coast. On the way home I hit it a bit harder and had 40 psi a couple of times and one roll at 60 psi. I then dropped the break in oil and filter, cut the filter and found powder coating flakes. Because of this I made another street run with a few roll ins on the new oil (20w50 racing) and again cut the filter to find things were much better.

From there the truck went on the dyno where it made no less than 40 runs at several hundred RWHP with ample coast down time between runs. I then drained oil and filter (almost no sign of powder any more) and went to the next Truck Pull...

My new LML will likely see early (controlled load) dyno operation as well. My "roll ins" are at hwy speed and I don't like to push my luck with getting a ticket...

Randy,

That's plenty of load. Maybe a bit much depending on conditions. Just take it easy and roll in and out without kicking down. This is tough for many as they face a lot of traffic. Here I have a 20 mile block that we run as a tow test when customers come in for tuning. It has a few short but steep grades and traffic is genetrally minimal. I also like to have a VERY good oil in place for this. The whole break in thing was discussed MANY years ago on the original GM Diesel Forum (The Diesel Page) when the Dmax was in it's infancy and those "in the know" agreed. All three of my trucks were broken in aggressively once the R&P were in the clear. There is a recommended break in from Eaton (not sure about AAM) regarding rear diffs, ring and pinions, etc and this was posted and discussed. The idea is that there is significant heat generated as they wear in and too much heat can soften the gears so short trips with ample cool down are recommended initially. To be honest, my 2005 and 2007 still have the original diff lube in them.

I'll have to sell or trade one to make room for the LML. Elaine won't let me have four Dmax trucks. I'm anxious to get ahold of one. Thinking the 05 (my keeper truck) will be the one that gets replaced and the 2007 (puddle jumper) will stick around a bit until the next short term opportunity arises.

For point of reference, the built 7.1 stroker in my 2002 was run in the driveway briefly to check for leaks and then we took it to town and then another 6 miles to grocery store. On this trip I rolled into it a couple of times making about 20psi boost at light throttle and then backed off to coast. On the way home I hit it a bit harder and had 40 psi a couple of times and one roll at 60 psi. I then dropped the break in oil and filter, cut the filter and found powder coating flakes. Because of this I made another street run with a few roll ins on the new oil (20w50 racing) and again cut the filter to find things were much better.

From there the truck went on the dyno where it made no less than 40 runs at several hundred RWHP with ample coast down time between runs. I then drained oil and filter (almost no sign of powder any more) and went to the next Truck Pull...

My new LML will likely see early (controlled load) dyno operation as well. My "roll ins" are at hwy speed and I don't like to push my luck with getting a ticket...

Good info, take to the bank folks.

I went to the Eaton site and find that they state that there is 'NO' break in period required for their assemblies; frankly I was shocked as there is so much information out there to the contrary.

I take it that you are going to get a new LML----that's pretty strong recommendation seeing as there isn't that much feed back out there yet!

Randy

I'm with Kennedy on this. :D Mike