Golden Gate RR Museum has several heavyweight passenger cars with the standard 9" wide friction-bearing journal boxes and 5" x 9" plain bearings.To convert these trucks to AP style cartridge roller bearings (the ones with the 3-bolt spinner cap), what is the best choice:- Machine old journal boxes? (We have been told that 5x9 RB adapters designed for freight car trucks won't fit into the old journal boxes without significant machining in a boring mill, etc.) - Make new welded journal boxes? (Napa Valley Wine Train did this; it's labor-intensive)- CNC mill new journal boxes from solid steel? - Are steel castings available?- Other suggestions?Thanks!Doug DebsGolden Gate Railroad MuseumSan Francisco, CAtel: (408)-433-2672 work daytimes 8:30am-7pmtel: (650)-856-3469 homee-mail: doug.debs@fcimg.com

contact the Cal Western shop at Fort Bragg Ca they have done quite a few conversions from 9" plain to roller bearing.

Before about 1990 the answer to this question in northern states was to go to scrapyards in Canada where 6-axle ex-CN cars were being scrapped by VIA, and collect both the roller-bearing wheelsets and the special journal boxes CN cast up to make this conversion in the 1960's. However, the few passenger-car operators who have these boxes squirreled away are not likely to have enough for your needs.(CN used 5-1/2x10" AP-style bearings on 5x9" centers, perhaps because these were heavy cars in 100-mph service. This was a tight fit into the 9-inch pedestals, and did not leave much material on the sides of the box around the bearing.)CN also converted 1930's oil-lubricated roller-bearing journal boxes to take AP-style NFL rollers by boring out the boxes to fit around the cartridge bearing. The result was a crude, hacked-up box, but it apparently worked. If there is enough room in your old journal boxes perhaps you could machine some kind of tubular adapter that you could weld inside, and then heat-treat and bore.It might not be too costly to make a pattern for replicating the CN journal-box casting, certainly cheaper than machining new boxes individually from stock. Other people with similar conversions might want these parts.Are you going to be buying all new roller-bearing wheelsets, or applying roller bearings to turned-down old axles? You may not want to reapply rim-stamped wheels if these cars are going to be subject to inspection by interchanging railroads.