Bettendorf Truck Ball Bearing Retrofit

Bettendorf Truck Ball Bearing Retrofit Vignette
(Retrofitting Aristo’s miniature ball bearings into the Bettendorf type truck side frames common to the 40 foot car types.)
Ted Doskaris
April 25, 2007
Revision GE-C

Aristo-Craft offers ball bearings, ART-29411, consisting of 10 miniature bearings housed within a single plastic vial. Since 8 bearings are required for a single freight car, 4 vials (40 bearings) will accommodate doing 5 cars. In this regard, Aristo offers better pricing for volume purchases for 5 vials – but a retailer must be reminded of this by referring him / her to the Aristo “Price & Production List” in order to assure the better pricing. For example, the Aristo “2007 Price & Production List” shows on page 16, column 1, ART-29411B Ball Bearing Set (50) at an MSRP of $100.00. Note the “B” suffix. Be advised these are not packaged any differently than a single vial as you merely get 5 of the same single vials at the better price - with many dealers discounting less than MSRP.

I used the new nylon material truck side frames samples I received from Aristo-Craft on Sept. 2006 for the installation described herein.
(Aristo has changed the heretofore plastic material to be impervious to the ill effects of some lubricants such as Electralube that has been associated with cracked journals. The Aristo factory production change over date to the new nylon material is not known.)
The same methods were subsequently applied to the older plastic material side frames with no difference in results.

Now for the installation process:

The Aristo-Craft Bettendorf side frame made of the new nylon material is drilled out 1/8 inch deep into the existing journal box hole with a 15/64 (0.234 inch) drill.
Due to the resilience of the nylon, I sometimes did the drilling with a slight amount of wobble to accommodate installation of Aristo's miniature ball bearings.

After enlarging the journal box hole, the side frame "spiral" flashing is removed using an Xacto knife.

The side frame hole is further trimmed by hand using a counter sink to establish a bevel to facilitate the installation of the Aristo's miniature ball bearing.

An Xacto knife is used to remove any excess flashing at what is to be the bearing flange surface area. The installed bearing must be completely flush with the side frame surface - otherwise the axles will bind when assembling them into the truck parts. As such, you cannot use the spread and twist method to install the axles as is commonly done with the plastic bushings.

The Aristo miniature ball bearing can be held with a pencil if gluing is required to retain it in a journal box hole that may have been drilled out a bit too large. Only do this if the installed bearing seems too loose or will fall out as a press fit is what will normally hold it.

If needed, the ball bearing should be glued into the side frame at its flange area only using a very small amount of CA glue. Using too much glue will risk freezing up the bearing internals!

Initially, the ball bearing is to be inserted into the side frame journal box hole with just a small amount of retention to just temporarily hold it.

The ball bearing is then thumb pressed into the side frame hole from the Journal Box side whilst resting the side frame with its semi retained bearing on a flat surface.

The ball bearing is completely pressed into the side frame hole by using your hand near the palm area to afford a bit more force. (Sometimes it’s OK to use a plastic mallet with minimal force to strike the journal box side - NEVER the bearing itself - to help with the installation.)

Shown below are side and top views of most of the ball bearings installed into the side frames. The bearings’ inner flange face must be completely flush mounted with the sides of the side frame whilst the flange thickness (lip) will be in view.

The axle tips can be trimmed with emery paper if needed to fit it into the ball bearing. Most of the time I did not have to do this, but sometimes they are too tight.

When assembling the side frame with its ball bearings onto the truck bolster with the brake shoe, I hold the spring using a very flat tweezer with one coil extending above the tweezer's tip. Some folks will glue the springs to the brake shoe as an alternative installation method. (Since the Aristo factory does not glue the springs, I always wondered how they assemble the truck parts together!)

Leave one coil exposed beyond the tweezer tip to allow for the spring to pop into brake shoe hole whilst guiding long end of spring into opposite side frame bolster spring hole.

I chose not to use the gluing method so I used a pair of tweezers with very thin bill shape ends to install the truck springs.

Sometimes I use two tweezers to install the truck springs. One to install the spring and the second to hold the spring whilst withdrawing the first tweezer, but much of the time the second tweezer may not be needed as the springs tend to pop in OK.

Below is shown the example completed truck assembly underside view with its nylon side frames and newly installed miniature ball bearings.
Note the flange thickness (lip) will still show but the inside area of the flange is not to be installed lopsided which would leave an irregular gap between it and the side frame.

Below is a better close-up view showing projected axle hub to side frame bearing clearance. This is with the axle at an unknown lateral placement.

I completed 4 truck assemblies with the nylon side frames and newly installed miniature ball bearings, and these were installed on 2 of my older PFE reefer cars.

Shown below are the first two of my older Aristo production run PFE reefers, ART-46201, that now have the new material nylon side frames and ball bearings. They roll along by themselves with just the minimal amount of out of level roadbed. (Including these reefers, I had previously retrofitted all my older Aristo production run 40 foot cars with the lowered floors and see through roof walks, too)

The following is a comparison made between Aristo Bettendorf trucks as they are with the standard plastic wheels and then with the ball bearing upgrade and metal wheels:

Below is shown the Aristo-Craft Train Accessory, ART-29101, that is a Bettendorf type truck with standard plastic wheels and no coupler. Again, this truck is mainly characterized by its "hot box" journals.

Below is shown the standard plastic wheels that measure a 0.151 inch clearance between its hub and side frame with its axle pushed all the way to the opposite side. (Note that the plastic wheels do not have a projecting hub like that of the ART-29111B metal replacement wheels. This hub projection is not to be confused with the overall tip-to-tip axle spread that is virtually the same for both plastic and metal wheel sets.)

Below is shown the automotive type gauge fan out stack used for the totalized 0.151 inch measurement.

More comparison:
Shown below is an Aristo example Bettendorf truck with installed miniature ball bearings into the new nylon side frames and retrofitted ART-29111B metal wheels.  The measured axle hub to bearing flange clearance is 0.051 inch maximum with its axle pushed all the way to the opposite side.

Note the below shown automotive type gauge fan out stack of only two used for the totalized 0.051 inch measurement. This is 0.100 inch less than the standard Aristo Bettendorf trucks with their standard plastic wheels and plastic bearing bushings - but it still has plenty of axle shaft lateral clearance!

It's been my experience that most of the axles will slide back and forth within the ball bearing sleeves of a truck without too much restriction but not so much as to be allowed to spin within it.
I have also found that adding two washers (each 0.015 inch thick) with one on each wheel end of an axle will provide for minimal axle side ply without introducing rotational restriction. Doing this appears to somewhat improve car operation on curves with respect to drag.


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