Quite a number of times in this site I’ve made reference to converting Tyco/Mantua trucks to OO, using a method first described in The OO Road by Ed Morlok. There is a specific type that works well for this conversion, and in working on a new batch for recent projects I realized that there is more than one type of these trucks even on Mantua/Tyco cars.

So first we have this comparison. the truck on the right is the type for the conversion. The one on the left is also Tyco/Mantua, but notice how the side frames are not as heavy/thick as the one on the right? For our purposes the truck on the left is useless, but the one on the right has a future in 19mm gauge.

Besides having the correct style of truck on hand, the other critical thing is to have wheelsets. In the past I mostly used HO 36″ wheelsets, but presently I use mostly HO 38″ wheelsets, which scale out correctly as 33″ wheels in OO. The one on the left is still HO gauge and on the right pulled out to 19mm using the tool seen (and also a NMRA gauge). There is only a short nub left visible of the axle, but that is all that is needed. If the end of the axle is damaged a bit, not an issue, just dress it lightly with a file.

Then you have to work the sideframes down to size. Most of the work I do in my garage (dirty work) shop with a big file. I rest the end of the file on the edge of my workbench and take things down to size.

After the initial rough work is done you take the sideframes down from what is seen on the left to what is seen on the right. From there you clean it up more and test fit wheelsets. Sometimes you have to drill out the axle holes a bit. In the end though you will have a very free rolling truck, as seen below on the right.

Of course with these trucks the mounting hole will be off center. I can adapt to that in most applications that I use these trucks. I rarely use these on vintage cars, with the exception of Scale-Craft flat cars where they are not very visible and the off center mounting works out fine. But I use these commonly on the various cars that reside in my “underscale fleet” described in the previous post.

They are not common, but there are Mantua/Tyco trucks of this type with a center hole, and I have used these on a few special cars. The snap on type are easy to find on eBay, but check the photos carefully to get the right type of heavy side frame truck.

You will be tempted to convert other brands. I have had some success with a type of AHM truck, but be warned that their plastic is softer, with more risk of failure.

How long does it take to make these? If I have my rhythm going I can knock out a pair in 20 minutes.

Finally, the comparison that matters is how they look compared to a Scale-Craft truck. Each one has problems to be sure. On both the wheelbase is too short for OO. Then the S-C truck has toy-like details. The conversion truck is small looking but then again more realistically detailed. In any case, they roll great and are worth trying.