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Improving The Performance Of AZL’s PA1

Reprinted from September/October, 2002, Volume 8, #5 issue of Ztrack Magazine, Copyright 1999, Ztrack, all rights reserved.

by Robert Kluz

Improving the Performance of AZL's PA1s American Z Lines release of the Alco PA1s last year marked a new era for the company. The PA1 was the first full width body diesel from AZL. The tooling and design work was completely different from that of their earlier released C44-9s. The sleek streamlined shells of the PAs and attention to detail from AZL and Ajin of Korea earned the PA1 Z Scale Product of the Year for 2001 by the readers of Model Railroader.

Interesting enough, the attention to detail that Ajin put into these units has also created demands on the operators. The PAs for instance run well on 220mm curved radius track. Binding may occur on any tighter radius curves. The reasons for this is the tight tolerances between the shell and the chassis as well as the addition of the cab ladder that extends down from the cab and falls adjacent to the front truck.

Minor adjustments were made to the locomotives prior to shipping. There are other enhancements that owners of these units can perform to improve the operation of these locomotives. Again, the issue is tolerances. Removing the chassis from the shell and running just the chassis demonstrates the full potential of the unit. Placing of the shell back on the chassis can be tricky as the placement is critical to prevent binding and hindrance of operation.

AZL PA1The tolerance issues are most critical around the trucks. The first area to examine is the aforementioned ladders (1 in the photo left). These ladders can prevent the front trucks from swinging to their full rotation. Without this swing, binding on curves can occur. By flaring the ladders out slightly, the trucks will be allowed to swing more freely.

The second area for scrutiny is that between the shell and the top portion of the trucks on the inside of the body (2 in the photo above). Here you will find brake details. These details can catch on the inside of the shell and hinder truck swing. These details have been modified slightly so they conform to the curve of the shell. Further modification may be needed if these details continue to hang on the shell. Slight downward pressure on the details will bend them slightly and prevent them from catching.

The final areas of review is the positioning of the shell and chassis as it pertains to the rear body mounted coupler and rear trucks (3 in the photo above). In this area, there is little room between the rear trucks and the body mounted coupler box. By positioning the chassis forward in the shell, the trucks will not touch the coupler box. On some locomotives, positioning the chassis forward is not possible (shorting may occur). Slight modification of the coupler housing is needed. When the trucks swing, the flanges of the wheels may touch the coupler box. This hinders performance and may cause a clicking sound when running around curves.

To improve performance, modify the coupler housing. A file or even an emery board can be used to gently file away and round the rear corners of the coupler box. Additional filing of the rear of the box will help to shorten the overall length. With this simple modification, the flanges will stop hitting the box and performance will increase. With these simple procedures, you may find your AZL PA1 performance increases.

As with other AZL products, a break in period is needed and your engine's performance will continue to improve over time. It is recommended to keep your track and wheels clean for optimum performance. Ajin has modified the E8/9 series to address some of these tolerance issues. The biggest change is the truck mounted couplers on the rear trucks of the E8/9s. This allows the E8/9 series to negotiate tighter radius curves. No doubt, you will find that these simple steps will only aid in making a great locomotive even a little better.