I just bought a 2003 duramax dually with 73000 miles to tow my 28ft enclosed race bike trailer and thought I got a good deal. So far i've gotten crappy mileage (the best being 13.8 mpg). Took it in to the dealer to check out and had a new air filter and fuel filter put in.after getting the truck back I noticed a vibration when taking off and coming to a stop, but it would go away immediately after I took off. I had tried the 4 wheel drive earlier before and thougt i put it back in 2 wheel drive. I stopped the truck and pushed the 2 wheel button a couple of times and the vibration seemed to have stopped until this past week and it started vibrating continuously unless i wasn't accelarating. Has this happened to anyone else and what should I prepare to get hit in the pocket for. your time and effort is appreciated.

bad vibrations in the drivetrain could be a couple different things. check your u joints. you've got three and they're a cheap fix to eliminate that issue. another possibility could be your front hubs. i was getting a slight vibration from my drivers side when it went out. lots of information on your vibration issues in the drivetrain section.

as for your mileage question. is that towing or empty? do you have the stock tire size or larger? don't be fooled by the very high mileage numbers that some post. i only get 15 mpg cruising around in mine and 18 on the highway.

Ryan,
Thanks for your reply, I was nervous about continuing to drive the truck like that and took it to the dealer tonight. I hope I can escape a bullet on this one. I am mechanically inclined and have plans to do any work on the truck that I can. I'm looking forward to continuing to learn all I can about diesels and thanks to people like you and this forum,I'm confident I'll survive it all. My problem right now is I have nowhere to work inside yet,and being from Minnesota, it's a little nippy right now and my truck won't fit in my garage. I will let you know the end results.
Thanks again

Oh by the way, everything is bone stock on the truck and the miles were non towing mph's

check the DIY section of this forum. there is a good write up on how to change the wheel bearings if thats the problem.

Ryan gives you good advice. Hope you get a good report from the dealer. I changed my front wheel bearing hubs myself following the instructions in the DIY forum. Really straight forward and saves a bunch of money over having the dealer do it.

Hopefully some dually owners will chime in with real world MPG numbers. I personally get about 15-16 in town and 18-19 on the highway when empty (not towing). Highway is at 70mph with cruise control on.

I get about that with my 07 classic

Thank you for the advice, and thanks to you guys and this forum, hopefully i'm going to learn something about diesel engines and trucks and how to work on them, especially with the price of diesel and the ecomony. Well............here's the skinny;my trouble was the rear shaft front u joint and I had a leaking seal. I got hit up for 800.00, ouch!!!!!!! and thats the last time hopefully that'll happen,i've done this a many a times on my cars. I just don't have a place to do it at right now but i'm working on it. My next DIY maintenance project task is to change my fluids. I need advice on what fluids I need and for what; rear end,transfer case etc, also what is the best additive for injector cleaning......also I was planning on buying an exhaust from the turbo back,which may take a minute now that I spent the money on this,darn......I just can't win, Love my truck though!!!!!!
Thanks again guys! I really appreciate your time and effort.

exhausts are cheap if you shop around. i'm also getting ready to change fluids in my truck. i'm rapidly approaching 100K miles and have a big service scheduled. i'm going to all synthetics with the exception of the engine oil. also putting gauges, cab lights, high idle kit and also the all headlight on mod. should be like a new truck when its all said and done.

I had a u-joint go out too, but mine was caused by a bad driveshaft. It killed the ujoint, tranny casing, and transfer case. That was a big bill. I also live in MN and we just got switched over to winter diesel which drops my mileage about 2mpg. I have overall average of 15.6 on the display but see 19-20 highway at 65-75 and maybe 15 town. I have a superchips microtuner, reg. size tires, and big exhaust, must help. It also will never really warm up this time of year either so mileage is hurt by that a bit too. Summertime you will do better.

Moved to Drive Train from the engine specific section!

Fill out a sig, and also let us know where you are, someone may be near you, and can come by and help out!

Can someone out there give me advice on how to get more hp and torque for the towing i do please. right now i'm getting between 8_9.5 mph when towing my toyhauler @ 65-70 mph which weighs 12700 dry and around 14000 loaded and I believe my max tow gvw is around 22 something. I want to buy a programmer and pipe but i'm totally lost when trying to decide what i need to buy and not spend my life savings. any help/advice is appreciated. i just had my injectors replaced a few weeks ago but she still feels down on power on inclines.

Hey!

For the guy lookin, I love my Banks but they are a little pricey. But the power is great and I like the safety features biult in. There are alot of different types check around and enjoy the ride beause it is a great ride:D

Can someone out there give me advice on how to get more hp and torque for the towing i do please. right now i'm getting between 8_9.5 mph when towing my toyhauler @ 65-70 mph which weighs 12700 dry and around 14000 loaded and I believe my max tow gvw is around 22 something. I want to buy a programmer and pipe but i'm totally lost when trying to decide what i need to buy and not spend my life savings. any help/advice is appreciated. i just had my injectors replaced a few weeks ago but she still feels down on power on inclines.


I say straight pipe the exhaust and save the money on that part, and as for a programmer, go with a Banks or Bully Dog for the safety aspects, and go, or you could get a set of gauges and run what makes you feel good, and you can watch the EGT's to make sure they are not going to the moon!


Just one opinion!