Week 5 "More sensor testing and the progress on the Detroit 60s assigment"

During this last week of class we spent a lot of time watching our instructor disassemble a 4.5 John Deere engine that had a hole in the side of the engine block. Neither our instructor or anyone in class had been inside this engine to see what exactly had happened. So we spent a couple hours each morning learning the proper way to keep foreign materials from entering the engine while disassembling. He was also careful to show us where to start our failure analysis for this type of engine failure.

We all had our own suspicions on what had happened and it turned out to be a broken stabilizing shaft. As to what caused the shaft to break, that is still an on going investigation.

We also had an assignment given to us that had to do with different types of sensors found on a Trucks or heavy equipment, explaining how they work and showing how they work using either a digital multimeter or a scope. Since in my last blog I posted on the testing of a ABS wheel speed sensor using the shops Modis and big screen, I figured I would test a temperature sensor using a digital multimeter.

In the left picture you can see that the temperature sensor has a certain electrical resistance at a certain temperature, it happened to be 10.816 ohms at shop room temperature. Now as we move right you can see in the middle picture that as soon as I pointed the heat gun on the sensor the electrical resistance changed in proportion to the change in temperature. In the picture on the right you can see this sensor had the same result when heat was taken away only in the opposite fashion.

Me and my group also made some great headway on our assignment on the Detroit 60s. Below are some pictures of some of what we managed to get done.

My group and I managed to get everything disassembled from the engine that we needed to, to be able to start taking all of the assigned measurements the following week. After spending several long hours staring and searching I was also able to find and print off all the specifications we would need to know if what we are measuring is in or out of spec.The link is below.

 http://www.kenmartransport.com/detroit/Series_60_Service_Manual.pdf

I think the thing I can probably reflect on the most over this last week, is how important the ability to to pay attention to detail is. For me this came up several times, once was when I was trying to explain to a fellow group who was having trouble removing the head from the engine block. They were using a hoist which should have picked the head right off the engine block, but for some reason wouldn't. They were 100 percent positive that they were completely unattached from the engine block but the head wouldn't come all the way off. It wasn't until someone actually wanted to hear what I had to say before I was able to show them, that no the head wasn't attached to the block. And that there problem was one little bolt head off the timing gear assembly that wouldn't allow them to remove the head. One little detail had 4 or 5 people tearing there hair out for a few minutes.
I also had the opportunity to remove a cylinder liner out of an engine. Something I had seen done but never had done myself, it was some what simple but new all the same.

Week 5
Hours 22