Well if you want engineers to do the job right you have to make it clear ,to the people who send them out to do the job, two things the first is that they will save money if they service the truck in the correct manner and the other thing is stop employing numptys and employ good engineers who actually want to do the job right and then allow them time to do the job.
My last employer was quite happy to send a painter out to service a truck with no knowledge other than how to change two filters oil filter and air filter and then they didn`t even give him the right engine oil. they were happy because he had turned up and fullfilled his contract of three services a year and the employer did it as cheap as possible.every body wins until two or three years down the line the truck stops the customer gets a big bill then next time it comes to buy more trucks you hear" them trucks are crap cost me a fortune" and they move on to the next manufactuer for another five years.