[Bradbub]

I just traded my 03 d-max extended cab in for an 04 with a crew cab. The Diesel manual says nothing about proper break in. I have 500 miles on it and have been taking it easy always varying my speed and rpm. Do you guys have any suggestions. My apologies if you have talked about this somewhere else on the sight. I did several searches but came up empty.


Thanks!!!!!


Bradbub

 

[srode]

I thought the same thing, it's in the Duramax Manual, look in the back in the index for the break-in. It wasn't easy to find, would have thought it would be on the first couple of pages, but it's buried in the middle somewhere. Says don't drive over 55 for the first 500, no heavy throttle either. Can tow after first 500, but keep it under 50 MPH for first 500 of towing. Sounds like you are ready to start towing!

 

[Bradbub]

I did read that but I just wanted to make sure that applied to the diesel as well. As much as I paid for the da_n thing I want to make sure I do it right!!!!


Thanks


Bradbub

 

[somekevinguy]

It is in the special seperate little owners manual just for the duramax engine. Of course it is for the duramax. You don't get that manual with anything but a duramax.

 

[GMC2500HD]

Well I guess I will be the one with issues later, I have been driving the hell out of mine since I picked it up. Talked to tech guy he said all the break in stuff was a myth. Guess we will see if it ever needs service.

 

[Bradbub]

Thanks guys for the Help!

 

[2MuchFun]

Thats rediculous! You could'nt even drive safely on the freeway here in So. Cal. at 50 or less!


I just take it easy on her, varying speed. After the first couple hundred, I'll run the motor up good and back out right away. In the first 500 miles I'll do that 3-4 times.


~~Break-in is all about varying the loads on the motor and not overheating. And NOT bogging it.


I also do the first oil change at 1000 miles and send it in for analysis.


So far, I've had very good wear readings.

 

[Zeeb]

Couple of things about the break in process.


First, it's not a myth. All the metal components that rub against each other will need to slightly wear into each other due to manufacturing tolerances. Or in the case of piston rings, they need to "seat" in the cylinders. Those tolerances are really small but differences do exist.


Second, you're not dealing with just the engine. The biggest reason for the speed restriction to begin with is the rear end. The ring and pinion gears need to get aquainted... And they'll produce quite a bit of heat doing that. If you abuse that process, I don't think you'll break anything right away, but oil seals could fail later on and you might develop a howl in the rear end at certain speeds or conditions.


Third, the idea of varying the RPM is a good one for purposes of seating the rings in the engine, and generally trying to drive it like you intend to do most of the time is also a good idea. Don't be afraid to punch it once in a while either, just don't let it rev up too high during that first 500 miles.


Just my two cents based on past experience.

 

[BlueDMax]

After the 500 miles of 'easy' driving and the '500' miles of easy towing get your rear end oil changed (make sure it is the GL5 synthetic). Eaton (make of the G80 locker rear axle) says the towing break-in can get oil temp high enough to degrade it. Others say you should change all your lube fluids after an initial break-in to get rid of manufacturing 'crude'.

 

[Dustin]

I bought my Duramax in March of 2003 and I have over 50,000 miles on it. The first day I had it our on the interstate driving 70. No problems so far, getting stronger by the day. K+N System, Straight Piped and Large and in Charge. Remember Real Trucks don't have spark plugs, Drive On!

 

[problemchild]

You all missed one very important point. Heat up and COOL down of the motor is just as important. Letting the engine get completely cold after running it is impostant.

 

[Zeeb]

Perhaps not missed but the assumption, and I know making assumptions can be dangerous....

,


is that the first 1000 miles or so wouldn't be accumulated all in one run. A valid point none the less.....

 

[k1xv]

The heating and cooling raised by problemchild is a very important aspect of break-in. To amplify on that point, various cast parts develop internal stresses as the parts cool from the casting process. Repeated heating and cooling over multiple heating/cooling cycles relieves those stresses. Varying engine load also causes temperature changes within the piston/cylinder/cylinder head.


Therefore, a light loaded 1000 mile drive all in one shot does not provide the same break-in as 1000 miles of short trips with varied driving conditions.

 

[Dmax Tim]

Drive it like u STOLE it.


J/K


I run mine but don't overly abuse it and the last 7 D/A had 7-10,000 miles on when traded and no problems.


I do notice a big change going from the old truck to the new ones, man they seem tight (the engine).


I run the oil changes by the computer and all have never had the trans filter or rear end oil changed.

 

[Bradbub]

Thanks for the feedback! Speedo is now showing a 1000 miles. I have yet to tow anything. Do you guys think I should change all the fluids? Or wait until I have 5000, like Eric talks about on his maintenace schedule. I changed the oil and filter a 500. I did have to add a quart of Juice to the rearend because it was a quart low.

 

[Zeeb]

This will be my first Dmax, but not my first new diesel or gas vehicle. Based on my experience and information I've gotten here as well as from local Service Managers and factory Tech Reps, I like Eric's schedule.


If you factor in Eric's experience and expertise, for me the choice is pretty easy.

 

[sky1]

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Bradbub , how do you check level of rear diff fluid? i'm at 2500 miles and would like to check it. what did you use for fluid? dont want to go to dealer.


THANX JEFF</TD></TR>
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[Bradbub]

Jeff, there is a plug on the back of the diff. A 5/8 socket seems to fit mine the best. Just remove the plug and check the fluid level with your finger. The manual says the level should be at 0 to a 1/2" below the fill hole. I used the Grape Juice. The dealer here will sell it to me for $21.00 a quart, which is still a bunch of Sh#t!!!! I am going to run GM's Dom Perione grape juice until my warranty is up.


Brandt

 

[inte]

Just to add a little controversey regarding break-in procedures... check out this link:


http://www.mototuneusa.com/break_in_secrets.htm


I just picked up my DMax this past weekend, so I kept it to city streets & the local hills for the first 260 miles, but have to hit the freeway today ... Dustin had his on the freeway the first day, so I suppose it will be fine...

 

[3500LLY]

Thanks for the link inte. I'll be getting my truck sometime in the next couple weeks. I've always heard that if you break an engine in hard it will run hard and that website gave some good info as to why, no controversy here.