2/16-2/20 Leaf Spring Replacement & Bearing Inspection

I spent the majority of this week working on the shop truck to replace the front leaf springs. The process was very straight forward, or at least it sounded straight forward before I got into it. I learned through trial and error, that the easiest way is to lift the vehicle is by the frame, support the front axle, detach the front shocks, then remove the shackle bolts and u-bolts to release the leaf springs as well as the front axle. The new leaf springs proved to be difficult to install. A few modifications had to be made so that the new springs would fit. In addition to getting new leaf springs the truck was also getting new rotors and having the bearings cleaned/inspected and repacked. I learned that in order to properly check the condition of the bearings they must be thoroughly cleaned before inspection. Each roller is inspected for damage as well as the racers. This can be achieved by shining a light through the back of the bearing to assist in checking for wear defects.

All in all this project was a great learning process for me. The mechanics at NWFR gave me the freedom to tackle this leaf spring project virtually on my own while they caught up on more time sensitive projects. They did make themselves available to answer any of my questions and made sure to check on me every once in awhile to ensure I doing alright. By the time I finally finished the leaf springs John was able to teach me about bearing inspection. I gained a lot of knowledge this week.

I neglected to take more pictures of the wheel bearings during the inspection process, it's hard to remember to take out your phone in the middle of a project to take a picture for a blog. 

Removing the u-bolts

Out with the old

As you can see the pin is larger on the new springs

This proved to be my greatest frustration, as drilling out the new hole to accommodate this larger pin proved to be quite the head ache.  

2/9-2/13 Electrolysis

We had one of the departments tenders in the shop last week for its annual maintenance. Part of the the maintenance procedure was a voltage test. While checking the battery voltage and output, we also checked the engine coolant for stray voltage. Curious as to how voltage could end up in the coolant, I asked how this could occur. I was told that an improperly connected ground wire could cause a short as the electrical charge tries to find the path of least resistance to a ground source. When this happens, the current degrades metals, often in the radiator, in a process known as electrolysis. This process does not take long at all, compared to corrosion which may take months to do damage, electrolysis may only take days to weeks for irreversible damage to occur.

Unfortunately, my phone does not want to upload the pictures of the sample cylinder sleeves that our instructor, Jeff, had on display for us. So I will upload the next best thing; google images!

 


Total Shop Hours @ NWFR for Feb.: 44.75
Total Shop Hours @ BTC for Feb.: 28

1/26-1/30 Cutting Torches

This last week we learned a valuable skill, using an acetylene torch for cutting 3/8th steel. This was part of our wrench assignment. Using nothing but a cutting torch, hacksaw, and files, we were instructed to craft a 2" wrench with an allowance of .014th of an inch. The acetylene for the torch must be properly mixed with oxygen for an effective cut. We were provided with sources to find what tip we needed for the torch as well as the fuel to oxygen mixture for the 3/8th steel we would be cutting.

Cutting 3/8th steel with a 0 size head with the O2 at 25/30 and gas at 3/5