Concerns about purchasing GM Diesel Truck

125-150,000 miles is almost broken in. Diesels (except for that 1973 Oldsmobile) typically go 300,000 miles (or more) before needing a rebuild. Rest of the truck ought to wear out before the motor.

That's no mileage for a well maintianed diesel truck. My '05 Chevy diesel, which I bought new, has 231,000 on it. I drive it every day for work and it's always loaded and/or towing. It's been the most reliable vehicle I've ever owned. I'll be really disappointed if I don't get to 300,000 miles before anything major starts to break.
The early Duramax in the 2001 - 2004.5 model years was the LB7, it had injector problems. I would avoid those. The 2004.5 - 2005 Duramax was the LLY, they don't cool as well as the others but otherwise solid. That's what mine is. The 2006-2007..5 Duramax is the LBZ. This is the best one, they hold their value extremely well. This model gained the 6 speed Allison instead of the 5 speed, gained HP, but did not have the DPF or DEF. Any Duramax after the LBZ was still a solid engine with no real problems but they did gain the emission stuff many people don't like.

You might try a used MDT or even HDT. Tough to sell, will pull anything, and run a million miles.

If you find one it doesn't hurt to have a dealer look it over. The big ticket items are injectors and head gaskets.

Last week you could have had my pristine 2007 Dodge Ram dually with 43,000 miles on it for 25K.

look for a stock 06/07 (pre-emissions), this will have the 6 spd transmission and LBZ engine (50 ft lbs more torque than the 05). I wouldn't worry about that mileage, 125-150k isn't much for a diesel if they have serviced it regularly (oil, fuel filter, driveline fluid etc). The 06/07 will get better mpg towing than the 07.5+ with the emissions equipment.

Low mileage 06/07 are desire-able, so prices may be higher.

Also the fuel tanks in the short beds aren't very big, my 08 has a 26 gallon tank, which doesn't last very long towing. If you tow very far, you might think about saving some money for a titan replacement tank.

Four years ago we purchased our 08 GMC Duramax DRW with just over 120000 miles on it. In the past four years we've had to replace the number eight glow plug, ABS modulator and upper control arms, if memory serves me I've spent less than $500 for these repairs.

My friend purchased a 09 GMC Duramax DRW with 230000 on two years ago and hasn't done a thing to it.

I paid $29000 for ours and he paid around $23000 for his.

Research the trucks you like and as you said have your mechanic go over it top to bottom. I personally don't think you can go wrong with a Duramax.

The one I just saw on Auto Trader was a 2005 for $13000. I would like to stay under $20.000 because the truck would be used for towing only..

What price ?