I'm looking to buy a 2005 or 2006 Dodge 2500 diesel, in the next few weeks if I can find one. But I don't know allot about them and what to look for when buying. The trucks I'm looking at have anywhere from 90 to 130 thousand miles on them, I'm trying to stay with the 5.9 because of MPG and dependability, also looking for a 3.73 rear end. This will be my first diesel so I don't want mess-up and get one that needs allot of work or that has been dogged out. Any help is appreciated, Thanks

 

When I was looking for mine, I didn't look at anything that had a 5th wheel hitch. That can sometimes be pretty hard miles.

I also avoided anything that had a tuner box installed.

 

I would recommend a manual transmission. See if the smokes a blueish white at idle on a cold start. Smell the oil to make sure it smells like oil. If eiither of these has issue then you could have leaky injectos and about 400 a piece to replace 200 a piece to repair. If still a factory exhaust location, look behind the bumper and under the fend for excessive soot. Not alot of folks clean that area and if heavy it has likely had a tuner(not a bad thing just something to negotie with). See if you can find any service records. The diffs are supposed to be done every 15k but you can get away with more. T_Case every 60k. Manual Fluid they claims is life time but if the truck has been ran hard i would suggest every 100k. Look at the exhaust housing to see if it has been really hot. Rear mail seal may have a little leak but i believe that is normal on a cummins. Look for heavy blow buy out the blow by tube. It shoudl be on the drivers side behind the front axle. If a lot it could be rings or valve guides. Alot would mean everything is covered about 1/8 thick. A very light coating is normal. Rear breaks should be f80% front likely 30%. If more than in that mileage range it was towing alot or driven hard. Again not bad thing just things to look for. You want to make sure the HVAC system is working and you get air flow out of all vents like they are supposed to. The systems is poorly designed and the doors break. Other than injector issues due to lack of factory filtertraition these motor are fairly tough. The only motor issue I have had on my 03 is injector in 150k of towing, stop and go, running my TST and driving it hard. Even with the injector a great running truck. My HVAC has the mentioned issues but still over all happy with the truck and wouldn't get rid of it for a new one with all the emissions stuff. There is load of information on this site to help you.