Where can I find an HO Scale Brass wheel outside trailing truck detail part? Thanks! 
The trailing truck has inside bearings-the wheel is outside.
Cole, Delta or Hodges?
Precision Scale makes a Delta truck. The Cal-Scale division of Bowser has (what looks to me like) a Hodges. Greenway Products also has a listing for a 2 wheel truck at their site, but the picture doesn’t show and th. You might have to email them.
Cal-Scale: http://www.bowser-trains.com/hoother/calscale/Cal-Scale-Steam-Loco-Parts5.jpg
For PSC, you’d need the catalog to see a pic.
You can get non-brass Delta trucks from Yardbird trains. They have both the old Mantua and Varney Delta trailing trucks.
Greenway Products also has a brass Hodges: http://greenwaybrass.com/img_ts/ts930.jpg
As well as a Delta: http://greenwaybrass.com/img_ts/ts934.jpg
Link to Greenway parts list: http://greenwaybrass.com/s_87_parts.shtml .
Greenway’s site can be sometimes a bit hard to navigate, so use the above link.
Andre
You can get a commonly accepted stand-in by using a regular 2-wheel lead truck. Precision Scale makes some. There’s 26" and 33" plain wheels and 26", 33", 36", and 40" spoked. The latter might do. Precision also lists 45" and 50" spoked wheels that you could use if you made up your own truck. I did this when I wanted to make an 0-8-0T into a 2-8-2T (but with 20" wheels).
Now, the thing is that trailing trucks aren’t exactly the same as lead trucks. The real ones have equalizing levers between the truck and the locomotive frame. Also, a lot of times the locomotive frame figures prominently as a visual element. Unlike the outside bearing trucks mentioned above, these trucks were custom built for each locomotive–any similarities would be co-incidental–it’d be FUN to build one! Really.
So, you have a choice of building a pretty simple trailing truck or a pretty complicated (and more correct) one. Your choice.
I’ll mention that some brass locomotives have come with trailing trucks that would probably suit your purpose beautifully, But I don’t think you’ll find too many modelers willing to part with one from one of their engines.
Well, it’s a start–good luck,
Ed
Man, I sure read your question wrong. OTOH, your wording was confusing.
It sounded like you wanted an outside BEARING trailing truck like a Cole, Delta, or Hodges.
Andre
Yea, I apologize Andre I did word it incorrectly. I know the different types of trailing trucks. Again, I apologize. Thats why I had to revise it after I read your post.