I have been looking for factual information on plain bearing to roller bearing conversions for the common rigid bolster switcher truck. In my search I haven't truly found what I think I am looking for so I hope that my inquiries here are well received and understood.

There are numerous points to consider/facts that come into play in the conversion.

-standard plain bearing is 6.5" x 12"
-roller bearing standard seems to be AP F (6.5 x 12) which is also consequently the same size and style as modern freight cars.

-there is a need to procure adapters for the AP style roller bearing into either the existing modified journal box (cut, milled etc)

OR

-there is a need to procure adapters for the AP style roller bearing into new or good used journal boxes specifically for the AP style/class of roller bearing.

-the plain journal axles can be used if the axle is turned down at the journal surfaces (for press fit of the roller bearing and its inner race) and the axle ends removed (flanges previously used to keep plain bearing in place by acting as a thrust stop).

While I understand the basic concepts behind the conversion I need your help to figure out the specific part numbers and shops/outfits that can perform the sort of work required to produce safe results on a budget.

Here we go:

1) Given a good set of plain bearing journaled wheel sets (better than 2 inch thickness) it makes economic sense to attempt to reuse those good wheelsets in the conversion. Is there an AAR certified shop or outfit that is known to offer services in the way of turning and fitting AP class bearings to extant axles?

2) Is there a list of part numbers with descriptions and perhaps distributors with good used adapters, boxes, conversion parts in stock?

3) Are there dimensioned diagrams/prints available that show the modifications needed for the plain bearing journal box to roller-bearing compatible journal box?

4) Are there dimensioned diagrams/prints available that show the modifications needed for the plain bearing axle/journal for the press-fit roller bearing?

5) Have any of you personally gone through this process and wish/care to share your experience with me privately or otherwise with costs, timelines etc?

6) Is there a specific print/issue of the Car and Locomotive Cyclopedia that details this process as there is for the 26FNL conversions for 6 brake equipped switchers and other locomotives?

I have been advised of a simpler route to this however I would still welcome additional insights.

First of all, unless you are planning on moving the locomotive witch currently has 2 inch wheels, why convert?

Second, do not count on all the axles to be good.
Friction/plain bearings tend to heat the axles up, causing heat cracks.
A friend did many conversions and told me to count on atleast 1 in 4 axles to be bad.

Third, there is NO cheap about this conversion.

If I needed roller-bearing trucks for any operational reason, I'd look at finding a pair of replacement trucks with roller bearings and modifying them as necessary to fit.

If I needed roller bearings to move the locomotive, I would supply them as freight-car trucks under suitable flatcars to transport the locomotive on blocks, and the trucks beside it.

If I wanted the locomotive for any historic preservation, I'd keep the plain bearings and talk to someone like Jason who's a tribology nerd and can advise you on good care and feeding of the existing journal and brass system.

The entire intent behind the conversion is to move the locomotive. Interchange.

Duly noted regarding the potential for cracks and other stress related issues with extant plain bearing axles.

Sure.


What has your experience been with this sort of move? It wasn't the question but my curiosity leads me to ask the follow-up.



That was not the question. :) But I'm curios, who is Jason?