Thinking of doing a rebuild on a DD15? DONT!

Agreed. All the old, good mechanics have long since retired, and most of the new guys don't know how to use a micrometer properly.

 

At least plasigauge !

 

Rebuilding engines is becoming a lost art. When I started about 25 years ago, it was nothing to see 3 or more on the go for rebuilds all the time. Now, we rebuild 3 a year!!! Many factors for this, engines do last longer and oils are way better along with better bearing and internal part longevity. Truck prices degrade so quickly and engines are way more complicated today that it just makes rebuilding no longer financially feasible with high labor rates. You aren't rebuilding engines for $6500 in 30 hours anymore. So you get guys that are building an engine once a year or so. Hard to be good when you do it so infrequently.

 

You just have to go farther to find the right guy for the job that knows what he's doing. The days of knowing all engines and chassis are history. Has nothing to do with knowing how to use a micrometer. You can't measure a main crank journal with it still in the truck anyhow.

 

Agreed. To add...

Crankshaft bearings on today's engines are much less forgiving than older engines. Tolerances are closed up to run lighter weight oil. Bearing compounds are much harder and dont absorb debris and particles like they use too, which means more crankshaft wear when metal or dirt does go through the engine. Not to mention most shops are not even close to clean enough of an environment to be building engines. Inspecting parts to meet reuse quidelines is critical. Factory reman engines are the best option and while more expensive they are more reliable and will have better warranty and prove more reliable in the long run.

 

The big issue with the crankshaft has been mismatched bearings. There are two companies that supply Detroit with bearings and their sizes are slightly different. You don't get mains in a top and bottom set. You get the uppers and lowers in two separate kits. If they do uppers with one manufacturer and lowers with another, they will spin and lock up pretty quick.

 

It's amazing how Lazy some techs are that won't even take the time to plastiguage the motor and CHECK !!

Don't complain when it fails and someone was too LAZY to even check for correct tolerances. Let it up to someone who knows what they're doing next time !

 

Detroit ain’t never built a decent engine! John Deere built one for them. 60 series

 

It seems like Detroit has gotten most of the issues with the DD15 fixed, and most shops are aware of the common issues. The pickup tube o-rings getting hard and leaking is very common, but they don't immediately fail. You will start to lose oil pressure, and it's up to the driver to pay attention and see that there is a problem BEFORE you completely lose it. Another problem is the fuel injectors. We've been seeing a LOT of injector failures around 250k-300k. Pre GHG17 motors will not set a fault for overfueling injectors, and there are not any tests that Detroit has approved for testing. A good sign that you have an issue is when you start to have constant issues with the aftertreatment. An overfueling injector will cause the One Box to fail if not caught in time. A good rule of thumb is if you do have to replace the One Box, also put a 6 pack in. Also, I've had to put a single cylinder in multiple engines due to an overfueling injector. The cylinder will get so hot that it will melt the bottom O-ring on the liner and cause coolant to drop into the oil. Detroit has acknowledged that there is a problem with the injectors, but they have not figured out a solution as of yet. They have acknowledged that they should have a service interval of 250k, but they will not document that because then they would be paying for injectors to be replaced under warranty. One last issue we have been seeing more of are valve seat failures. In the last two months, we've had three engines come in with a misfire and have found the valves stuck in the heads. This is fairly new and they're happening after about 750k. I'm a lead engine guy at my shop, so I make sure everything that has a measurement is checked. I also make sure the other engine builders check they're stuff. So many people don't know how to set an overhead adjustment, measure liner protrusion, mike out a liner or a crankshaft journal, etc. Engine building is an art. Yeah, anyone could tear down and put back together an engine, but you reallly need to know what you're doing to make sure that there are not any issues with it and to find out what CAUSED the failure. If anyone needs any help or advice on a Detroit engine (60 Series or DD), Caterpillar, or Cummins (ISB-ISX) then just reach out to me. My specialty is engines, mainly Cummins and Detroit.