New to diesels have some questions!

[Tray B]

Hello all,

I am in the process of buying a 03 Crewcab 4x4 Duramax/Allison truck.
I have never owned a diesel before and would like to know what is required in respect to normal maintenance.
I have read about fuel additives. Is this necessary/required?
How often do I need to change fuel filters?
Essentially I need a FAQ on what is required to maintain a diesel engine!

Any advice/info appreciated!

[volcano4x4]

First you read your manual...it will give you all the basic info you need to know about your truck.

[cmtndmax]

Tray B welcome! hang out here and you will learn a great deal about your new truck. use the search function sometimes it takes a while to weed through all the info but it is time well spent. don't be surprised these engines take at least 10k to 15k to break in. @ 20k mine just gets mo & mobetter. clean fuel & regular oil changes make for a happy diesel.

[403turbo]

Tray B

Welcome aboard! Congrats on the new truck.

Well normally this would seem like a simple question, however, you have wandered into the meeting place of the biggest group of fume smelling, smoke breathing, whistle junkies around and there will be many passionate opinions on this seemingly simple question.

You can never go wrong with the manual's recommendations. Be sure to follow break in procedures and don't be too disappointed if your truck doesn't tow well for the first 5K or so. They take a long time to break in.

The biggest single issue with the Duramax is clean fuel. You will find many members use aftermarket fuel filters to try and protect the high pressure fuel system from wear. Changing the fuel filter on a regualr basis is important.

Under normal conditions using a quality oil you can drive 7.5K or so between changes, more if you use a synthetic and/or analyize your oil to check for wear.

The allison has a spin on filter than can be changed for $20.

The fuel additive is a hot topic. A lot of members do use an additive. Power service, Howes, there are a bunch. There is some evidence that those that use an additive have fewer fuel system problems, but thats still a debate.

The other thing I have noticed coming from a gasser is noises. If you are the kind of person that freaks out when you hear a new noise this truck will take some getting used to. Mine has had "the tick" "the clunk" and a few other strange sounds that come and go but never cause a problem. There is that one noise we all love "the whistle" it kicks in around 1600rpm and is usually followed by a huge grin on the face of the driver :D

Congrats on the truck and welcome. You have found the single best resource for owners of the Duramax Trucks!

[Tray B]

Thanks for the info!

Turbo, How much oil does the Duramax hold? I know the the odl F*rd 7.3 held almost 5 gallons. Is the Duramax similar?

Thanks

[Waypoint3D]

Congrats! Tray B ....10qts w/filter for an oil change. Once you get use to the Dmax, you'll never have anything else smile.gif

[Tray B]

So other than having to change the fuel filters out and maybe adding fuel additives nothing out of the ordinary to running a diesel engine than gas?

[SparkyTX]

Originally posted by Tray B:
So other than having to change the fuel filters out and maybe adding fuel additives nothing out of the ordinary to running a diesel engine than gas? I, too, am new to diesels. My 03 GMC 2500HD 4x4 CC SB is my first one. And my baby just turned over 1,000 miles. She also had here one-month birthday today (from the date it was actually manufactured).

You might search this forum for 'break in'. It will give you some good pointers and recommendations that aren't in the manual, but aren't bad ideas either.

But your basic understanding is correct. Buy quality fuel, change your oil as recommended, buy quality filters, and don't forget to change the fuel filter (which is something rarely done on a gasser) and you should be okay.

You can also go to HowStuffWorks.com (http://www.howstuffworks.com) and get detailed information on exactly how a diesel works. Any more questions... search and ask.

And from one new oil burner to another... welcome.

[White Knight]

A couple of suggestions:
1) Change the rear end lube at 500 miles.
2) Change oil and filter at 500 miles.

Earlier, someone suggested changing the transmission spin-on filter. I agree! Don't forget to take the magnet off the top of the old filter and reinstall on new filter.

Lubricants are cheap. Both the above will give a good flush to get rid of some of the "stuff" in the systems left over from the manufacturing process.

Sam

[403turbo]

For a "light duty" use thats about it. In your part of the country cold starts shouldn't be a huge issue. Up north extreme cold starts call for some TLC.

If you are planning on towing heavy loads, 10K lbs or more you should take some other steps such as changing trasnmission and differential fluid on a regular basis. I bought my 'max used and changed the diffy fluids at 30K the amount of metal on the magnets was scarry! It looks like the first owner did not follow break in procedures. (not a good feeling) :eek: The hitch was still painted on the inside so I know that it wasn't used for towing, (the only saving grace).

The allison has been tortured by members of this forum and anything south of 425 flywheel horse seems to be acceptable to the tranny. The "limp mode" can be scarry to experience but keeps the drag racers from blowing parts all over the road. The transmission is awesome!

I will say that the 01 and 02 trucks could probably have a tougher front suspension. Tie rods have been a small problem for some owners, regular greasing is a must.

Basically maintenance is the key. The motor and drivetrain will last 300K if taken care of. There are members here (BROKERS) that work the sh*t out of the duramax everyday and are very pleased. For us "casual" users a little TLC goes a long way.

[Tray B]

WOW! :eek:

Thanks for the good info folks!

I will not be towing heavy loads often. Mostly I bought this to pull my boat. Its only about 4500-5000 #'s at most. We have been pulling this with our Tahoe and it does ok till you get to any kind of hill. It can tow around 65mph ok. Anything above and it has to work pretty hard. We tow the boat at least twice a month 5-6 months out of the year. We plan on taking a trips to lakes that are 500+ miles away.
I know its overkill but I think more is better than less! tongue.gif
The tuck I want is 450 miles away. The dealer is a friend of mine and has a driver that has been fetching vehicles for him for almost 20 years.
Any problems with driving almost 500 miles during break-in?

Thanks,

[Waypoint3D]

Any problems with driving almost 500 miles during break-in?
Mileage is not the problem, it's how it is driven during the break-in period. You'll hear a lot of different theories, safest is to follow the recommendations in the owners manual.

[SparkyTX]

One thing that is not in the owner's manual for teh first 500 that I would recommend is to stop after the first 20 miles or so and let the rear end cool down before continuing on the rest of your journey. Got get an ice cream or something. Let it cool for about 20 minutes prior to proceeding.

This comes from experience building rear-ends in big off-road trucks. The break-in period for differential gears is very critical. For rigs that will someday be exposed to heavy demands on the rear diff (large towing loads, oversized tires, etc), the proper conditioning of the metal ring and pinion gears is critical. Doing this will help to assure proper heat treatment to start with and will greatly increase your lasting endurability.

If you don't do this will you have issues later on? Quite possibly not. But it is real cheap insurance.

Once you get home, change the diff oil. Especially if you have a locker (G80 option).

[Tray B]

Sparky,

Thanks for the tip. What type and quantity of lube for the diff? It is a G80.

[Black95TD]

Tray B

Just a word of caution. I've had several diesels - VW, Chevy and Yanmar and on several occasions have had a bad load of fuel. I was changing my fuel filter on my 95 k2500 6.5 and noticed that the fuel looked like someone had dumped used crankcase oil in the fuel. Didn't notice and particular problem at the time. Once with my VW, had a bad load and notice lots of smoke out the tail pipe. Bad fuel sure could raise hell with fuel injection pump, injectors etc. Read a recent article indicating that a relatively high percentage of diesel fuel does not contain all the necessary additatives for lubrication! In the last two years I've had great luck per the following: 1) I only buy fuel from a local dealer that I know. His fuel is adertised as "premium" and I know he is careful about water etc. and 2) I use Stanadyne's Lubricity formula - a concentrated detergent and lubricant, to be sure the pump and injectors are properly lubricated. Because of air polltution concerns, we're using low sulphur fuel that does not lubricate as well as the old fuels. I think if you're careful to follow the recomended maintenance and use good fuel you will have great luck with your diesel.

[sdaver]

you will love it.......and welcome :D dave

[pinehill]

It was mentioned earlier that the red, spin-on tranny filter should be changed. The recommendation from Allison, not mentioned in the GM owner's manual, is that this filter should be changed the first time at 5,000 miles to preclude reduced fluid flow caused by particulates from the manufacturing processes.