Replacing bolster pins with screws...

[jargonlet]

For a while now I have been toying with the idea of replacing the bolster pin in some of my freight cars with a screw. I got started thinking about it while trying to improve the reliability of my PRR Bowser hoppers. I have body mounted the couplers in my older Bowsers and now none of the pins want to stay in. I’ve replaced many of them because most of them broke off when I removed the trucks to body mount. I’ve glued some in but I’m not convinced that this is the best solution. I was thinking about tapping the hole and using a screw like in ho. I’m also thinking that this would allow better fine tuning of the trucks since you would be able to tighten loosen the screw compared to the typical methods. Either way I have to do something with my bowser cars as they are not reliable currently.

Has anyone else done this? If I convert my bowser hoppers over successfully I may convert the whole fleet.

[Rasputen]

I've done this with MT hoppers in order to add more weight.  I used 3-48 pan head screws.  To stop anyone from over tightening the screw, I made a brass bushing for each truck that is about .008 inch longer than the thickness of the truck.  The bushing also takes up the difference between the thread OD and the ID of the truck bolster.  The no. 3 screw is about perfect for the MT hopper chassis, although I still ran the appropriate tap drill down each hole to make sure they were clean.

[Lemosteam]

What I do with MT pins when they lose their grip is flatten the press in end of the pin with some small flat head pliers to make it ovular. Then press it right beck in.

[jereising]

I had the same thought, so I bought a pack of these from Amazon:
Steel Thread Rolling Screw for Metal, Zinc Plated, 82 Degree Flat Undercut Head, Phillips Drive, #2-56 Thread Size, 3/16" Length (Pack of 100)
I've used nearly the first pack and ordered more; the plan is whenever I need to pull a pin I intend to replace it with this screw.  It gives very precise control over the wobble of the truck, necessary especially on longer cars.  I've not yet had an overtightening problem, probably because I want some wobble.  Tapping was not needed.  I'm very happy with the results.  Should have done it sooner.

[Cajonpassfan]

Thanks Jim, got a link? I’m getting all kinds of nonsense....
Otto

[nickelplate759]

Thanks Jim, got a link? I’m getting all kinds of nonsense....
Otto

I went digging through Amazon and found a page for them, but the are "Unavailable"

[C855B]

I'm not a fan of bolster screws, and recommend sticking with the pins. This is from my HO days, where bolster screws are common practice. They tend to move with use, either loosening or tightening, with predictable outcomes in increased derailments. The problem is the onset is gradual, so you never notice it until you start having mysterious problems that may or may not be traceable to a particular car.

FWIW.

[jereising]

I think this one will work nicely:

https://www.amazon.com/Thread-Cutting-Plated-Undercut-Phillips/dp/B00GX0J8AY/ref=dp_prsubs_2?pd_rd_i=B00GX0J8AY&psc=1

I've not seen any issues crop up as yet re moving screws in more than a year.  If that were to become a problem, you could probably just use a threadlocker...or some tacky glue.

[Cajonpassfan]

Thanks, Jim! Ordered.
I’ll try them on a few problem cars where the “squeezed pin” approach doesn’t seem to work for me in the long term.
Otto

[CRL]

Doesn’t MT include 2 sizes of bolster pins, with one being slightly larger than the other “stock”one?

[nkalanaga]

They do now.  It seems to be a relatively new thing, as I haven't seen it before.  On the other hand, I haven't bought any MT trucks for several years before now.  One is the regular size, the larger for Atlas.  I didn't know that Atlas cars had a different sized hole.  They didn't used to!

[Ike the BN Freak]

They do now.  It seems to be a relatively new thing, as I haven't seen it before.  On the other hand, I haven't bought any MT trucks for several years before now.  One is the regular size, the larger for Atlas.  I didn't know that Atlas cars had a different sized hole.  They didn't used to!

Not sure how new the two pins are, but they've had two different pins since I started in N 20+years ago.

[nkalanaga]

It's probably been that long since I ordered trucks from them!  I stocked up years ago, and still have a box full of old Atlas trucks from the 70s.  Put modern wheels in them, plastic or metal, and they work just fine.  Plus, since most new cars don't need to have the trucks changed, there's no need to buy trucks.

The recent purchases were 100-ton trucks, and Andrews for my GN 2-bay hoppers.

[mecgp7]

What about small screws with nuts? Drill through the bolster pin hole, insert screw, and add a nut. Leave a little length on the screw and you could add more nuts if you preferred to add more weight. Obviously won't work on all cars.

[dem34]

What about small screws with nuts? Drill through the bolster pin hole, insert screw, and add a nut. Leave a little length on the screw and you could add more nuts if you preferred to add more weight. Obviously won't work on all cars.

Nuts don't really grip the screw the way plastics do, they get loose very quickly unless you glue the threads, which is kinda sucky.
A sticking point on a piece of rolling stock on my bench right now since I need to glue the floor to the sides but the the material its made out of isn't suitable to tap into and the bolster screws keep coming loose.