Installing Kadee Trucks - #562 HGC Self-Centering Two-Piece Fully Equalized

Model Railroader General Discussion (Model Railroader)
1

I received a pair of replacement trucks today for a Kadee covered hopper. I want to make sure that I do the installation correctly, so I am looking for help and advice from members familiar with, and experienced in, installing these trucks.

Here is the pair of trucks with mounting tabs still in place holding the mounting screws.

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One set of instructions talk about making some modifications to the bolster on the underside of the car body.

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When those instructions say to “cut off flush” and "be sure top of hub is smooth and flat, are they saying to file off the four little pyramid shapes around the screw hole, as shown in the third photo?

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I appreciate any knowledgeable help and advice. No speculation please!

Rich

2

Here is the other set of instructions. Some of the terminology confuses me. For example, when the instructions say, drop the centering bushing into the truck bolster making sure the triangle wedges are indexed properly, I go blank.

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3

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Removed as there is now a better specific discussion.

Everything you need to know about how these trucks work can be found by referring to the relevant patent:

https://patents.google.com/patent/US7434518

You can clearly see there only has to be ‘one’ sideframe and bolster assembly manufactured; two of them interlock together mutually, with the two half-cylindrical bearing areas defining the ‘working’ surface for truck pivoting. That is why the truck bolster is in two pieces like that.

The upper part of the bushing acts as a fixed pivot pin, of somewhat larger OD and bearing surface than usual, and the flange acts as a stop to keep the truck frame from coming off. The self-centering action is simply a consequence of introducing wedges and grooves that induce the truck to swing wheels-parallel when lifted completely past the ‘bearing zone’.

All the alignment issues have to do with getting the wedges on the bearing pin at the right angle that the trucks ‘center’ to. This does not matter to the truck performance in normal running. It only affects the angle the truck assumes when the car is lifted.

4

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Removed as there is now a better explanation.

5

As the owner and operator of about 800 pair of Kadee trucks, I will go out on a limb here and suggest that I am qualified… At least a third of my Kadee trucks are the self centering type.

Rich, the self centering truck, as you have likely seen by now, has a bushing that the truck pivots on.

The hole in the truck bolster that receives the bushing has V shaped recesses on each side.

The bushing has matching V shaped protrusions on each side.

For the initial installation of the bushing, it does not need to be perferctly positioned, it simply needs to fall down into the little V in the bolster.

Then install the screw, most of the way, but not fully tight.

Hold the truck in a straight position as if the car was on straight track, pull the truck away from the car, this will engage the V of the truck bolster with the V of the bushing.

Holding the truck in this position, tighten the screw.

Flip the car over and let the trucks hang free, the should be in a straight line with the car body.

If not, loosen the screw very slightly, and turn the truck as far as it will go in the direction necessary for the adjustment until the bushing turns slightly,

Retighten and recheck.

When the car is sitting on the rails, the little V notches do nothing, they only engage when the car is lifted to “center” the trucks, in theory making it easier to place it on the rails.

The self centering feature itself is of marginal value in my mind, but, the fit of the bushing in the bolster is much better than just a screw, or even the bolster flange on the “average” freight car.

The self centering feature works the same on both sprung metal, and HGC equalized versions of Kadee trucks.

Questions are welcome, pictures may be possible if needed.

Sheldon

6

Rich, since I don’t own any Kadee hoppers, did the trucks you removed have the center bushing or just a screw?

The answer to this will effect the solution to the four little points on the car bolster.

As soon as I can, I will check out one of my Kadee box cars.

Sheldon

7

At the moment I’m away from the shop but I DO believe those three “nubs” can remain on the center sill/car bolster of your hopper car.

The part of the “centering bushing” that engages the carbody has four indents in it (you can see evidence of them in my caboose photo in the “Six Wheel Heavyweight” thread.

I will confirm this in an hour or so when I return to the layout room.

Good Luck, Ed

8

Now, having explained all that so that you hopefully have some idea of how the truck mounting works, it should be possible to simply install the trucks, with the screws, bushings and clips still together as the come out of the package. Screw them on to the car part way, remove the clips, and the pick up where I described the procedure for centering the bushing.

This should prevent the HGC truck two piece bolster from coming apart.

But generally, the clip on brake rigging does a good job holding them together in any case.

Sheldon

9

That’s what I am thinking as well, but my inventory of Kadee cars is limited.

Sheldon

10

Like most Kadee products these trucks are both simple and cleverly designed. Kadee separates the mounting surface from the rotation surface thus Kadee controls how the truck operates under the car. The bolster mounting surface must be level and flat (and those Kadee cars you have appear to have four nubs that achieve this aspect). The mating surfaces of the bolster and the top of the truck do not slide against each other. The rotation is between the center bushing and the hole in the truck. You don’t want to lubricate a Kadee truck for this reason.

By “indexing” Kadee simply means that the center bushing should fit correctly in that hole in the truck. It’s a complex way to describe a simple idea: " make sure the bushing fits the hole". The wedgy extensions on the sides of the otherwise round bushing are what “index” the bushing across the car and in turn index the trucks so they too hang exactly across the car with the wheels in line with the track to make rerailing easier. This feature also helps the car track better almost like the self centering of the steering on your road car, simple but clever.

The bushing will be snug to the bolster on the car when the mounting screw is tight. Whether the nubs need to come off or not may depend on coupler height. The center bushing does not move when the truck is screwed on tightly. The trucks rotate around the bushing.

The trucks will always seem to be loose. That’s how the truck self centres when you lift the car off the track and allow the trucks to self center as they hang from their bushings.

I find you can install the trucks with the car upside down just as for any other truck, contrary to Kadee’s weird instructions. However, as you snug down the screw the center bushing will rotate with the screw, clockwise and out of correct alignment. The trick I discovered is to first turn the truck complete with bushing counterclockwise just enough so that as the screw gets t

11

Kadee’s instructions made the installation sound a lot more involved than it actually is. Basically all you need is a flat mounting surface on the body bolster, and a properly sized hole for the replacement screw. Given that it’s a Kadee car, you shouldn’t have to make any adjustments for coupler height.

If the new trucks work OK on the stock bolsters, no additional modification should be required. If the protrusions on the car interfere with truck movement, trim them flush.

I’ve installed quite a few of Kadee’s HGC trucks. They’re a great solution for cars that have poor reliability caused by the truck/body bolster interface.

12

Yes, the truck that I removed has the center bushing. And, there are matching V-shaped cutouts on that center bushing to mate with the V-shaped protrusions on the car bolster.

Rich

13

So, if I understand correctly what y’all are saying, I do not file off those four little V-shaped protrusions on the car bolster. Is that correct?

Rich

14

That would be correct:

Kadee_hopper-bolster by Edmund, on Flickr

The instructions are aimed at those modelers who choose to retrofit Kadee self-centering trucks to any number of different designs of mounting bolsters out there. They can’t possibly hold the hands of every modeler who attempts to perform such a task. The instructions are simply a guide that indicates a flat surface is required for the “centering boss” to engage with.

If you already own a piece of Kadee rolling stock it would, it stands to reason, be designed to accept a Kadee truck.

This shows the centering boss if it were to be installed without the truck so you can see the indexed points at 90° intervals that engage the mating points on the carbody.

Kadee_centering-boss by Edmund, on Flickr

I hope that helps, Ed

15

Three? Or four?

Rich

16

Again, I was away from the shop and looking at your photograph on a less-than ideal internet connection.

FOUR

Kadee_Four-nubs-1 by Edmund, on Flickr

(The far-right “nub” in your photo was difficult for me to see clearly)

My Mistake, Ed

17

[quote user=“gmpullman”]

richhotrain
Is that correct?

That would be correct:

Kadee_hopper-bolster by Edmund, on Flickr

The instructions are aimed at those modelers who choose to retrofit Kadee self-centering trucks to any number of different designs of mounting bolsters out there. They can’t possibly hold the hands of every modeler who attempts to perform such a task. The instructions are simply a guide that indicates a flat surface is required for the “centering boss” to engage with.

If you already own a piece of Kadee rolling stock it would, it stands to reason, be designed to accept a Kadee truck.

This shows the centering boss if it were to be installed without the truck so you can see the indexed points at 90° intervals that engage the mating points on the carbody.

Kadee_centering-boss by Edmund, on Flickr

I hope that helps, Ed

18

Thanks for that clarification, Ed. I just wanted to be sure that I understood what your were referring to.

Rich

19

Sheldon, I have read your post a half a dozen

20

Those nubs will “index” that bushing for you.