The last several days have been spent working the P2k tune up tests. The activity has been fruitful and is summarized below:
1- the second GP9 is fitting in nicely. It’s as received test showed it also suffers a number of performance issues.
2- the other four engines successfully finished the second
set of tests. The motor was cleaned and lubricated.
3- All four demonstrated a performance criteria improvement.
4- The GP7 showed the least, because it lost some pull force. The others all demonstrated a healthy improvement.
In the process, the architecture of the five units was identified to be from three different production types.
1- The GP18’s were from the early production. The shell was held on with tabs. There was not much excess wire. It is like no maintenance was expected on the motor or truck towers. Which is what this is tune up is about.
2- the GP9’s both have the modified chassis. Here the coupler pockets fit in slots on the shell and hold the shell in place. There is a light board, but they are not DCC ready.
3- the GP7 and GP30 are essentially the same as the GP9’s, but these are DCC ready.
Because of the complexity of the first architecture, the truck bearing step is being evaluated on the third configurations. If the benefit on these two is small, then all of the truck work will be included in one step on the other three engines.