I haven't posted to this thread in a while. I do so now as I had five SDs on my workbench recently for chassis servicing, repairs, and tune ups. This is an unlikely event for a doorstop guy like me. Here is a photo of three of the five, taken just today:
These are all CLW models, two SD40s and an SD40-2. They are out for a test run on our layout's tightest curves, which are approximately 50" radius. One unit required several modifications to the trucks and drive shafts to get it to navigate that curve, while the other two handled the curve just fine as is. Other random issues included a loose side frame (caused by a missing screw), a melted plastic Kadee coupler ('splain me that), and a loose journal retainer. Happily, all ran well -- and ran well together -- when it was all done. I generally don't get that kind success on a single pass, so it was a good day. The modern cars behind the diesels were on the layout today as proof models -- we are raising the clearance of a 1940s truss bridge to accommodate today's car heights. Yea, we have a gauge, but we thought it wise to check the real thing.
The other two SDs to wander into the shop were these chassis from a pair of USH SD45s:
I agreed to repair these sight unseen, optimistically thinking it would be an afternoon's effort. It was, and about five more after that. One unit had a a split gear and a motor that ran hot. I was curious as to why, and swapped every part of that motor with a new one before isolating the problem to the armature. That felt like a lesson in learning nothing (which is itself a lesson). I put the new motor back together and put it in. The other chassis arrived in pieces, missing a motor (another motor!), drive shafts, and all sort of miscellaneous hardware. The only satisfaction I got out of that one was validation of being an accumulator of chassis and drive parts. Still, nice to see them complete and running nicely before packing and shipping them off.
Jim