Lionel "Late AAR" trucks...?

Don't take this as the last word, but I think you'll find the "late AAR" trucks will have plastic side frames (+ a different "look"). The bar-end trucks will be a metal part.

Bar End Metal Truck

Plastic Roller-Bearing Truck 

Thank you for the clarification.

Sight-unseen, I am considering a rolling stock car that was produced from the 1950s through the mid-'60s, and I'm trying to determine if it's worth the few extra $$ to go for the earlier issue with "real" metal trucks. 

Now I see that yes; yes it is.

Thanks...

The thing is, with some of the later cars, the plastic roller bearing trucks were standard.  If I recall correctly, plastic trucks began appearing around 1958.

Rusty

To further your inquiry on AAR trucks, Lionel had 3 types of AAR trucks, the earliest version used a diecast metal knuckle in the plastic frame held by a rivet similar to bar end trucks. then Lionel got a little cheaper and used a Delrin plastic knuckle in the AAR trucks, and finally the cheapest version which is actually considered the "late AAR" has a fixed knuckle coupler that does not operate.....hope that clarifies AAR trucks for you...…………………..Pat 

Hello Pat--

That is precisely the info I was looking for. Thank you. Due to space constraints--and my daughters having little interest--I have sold off most of the family heirloom 1950s trains but just kept a basic consist that gets pulled behind the ol' 682 along the 2-piece layout diorama that fits around the tree every Xmas. There is one particular rolling stock car I am interested in that was produced a few times from the 1950s/1960s, and I will spend the extra money for the early type in order to avoid the corners-cutting plastic trucks.

@harmonyards posted:

To further your inquiry on AAR trucks, Lionel had 3 types of AAR trucks, the earliest version used a diecast metal knuckle in the plastic frame held by a rivet similar to bar end trucks. then Lionel got a little cheaper and used a Delrin plastic knuckle in the AAR trucks, and finally the cheapest version which is actually considered the "late AAR" has a fixed knuckle coupler that does not operate.....hope that clarifies AAR trucks for you...…………………..Pat

There actually is a little bit more involved in the variances with the coupler knuckle design used in the postwar AAR trucks.  They did use a die cast knuckle & rivet in the early stages and switched over to plastic knuckles as you correctly stated, but during the final years of postwar production the plastic knuckle had undergone some tweaks, notably there was the plastic knuckles with rivets and "rivetless" knuckles where they simply added a dimple on the upper and lower part of the knuckle joint that slid into the knuckle holes in the main coupler to hold them in place and still allow them to open and close.  This is also where they went with what Lionel would refine a bit more during the MPC era where thin plastic sprues were designed into the knuckle mold that provides the "spring" action to pop open the couplers when the tab/plunger was pulled.  These coupler knuckles sometimes are found with a bit of a reddish appearance in the plastic, not entirely sure what the rhyme or reason was behind that.  There was also a period where a thin, narrow strip of what I assume is copper that was used as the spring before they went entirely to plastic.

A tad off topic here, but the plastic tucks have some good play value in my opinion: 1. you can add a car with plastic trucks without cutting off poweer, and 2. if you don't get them on correctly, and start up, they don't short out the power!

@wb47 posted:

A tad off topic here, but the plastic tucks have some good play value in my opinion: 1. you can add a car with plastic trucks without cutting off poweer, and 2. if you don't get them on correctly, and start up, they don't short out the power!

Plastic trucks don't actually play a role in preventing shorts on the rails in that situation.  What actually causes the typical short when a car is incorrectly put on the tracks is the metal wheels and axles.  When any part of the metal wheels come in contact with both the inner 3rd rail and an outside rail, like what happens in a derailment, then an electrical short is created.  So that will happen with both plastic and metal trucks, because the metal wheels and axles aren't electrically insulated from each other.  If the wheels were made of plastic (which Lionel did use on some rolling stock starting during the MPC era, or if one side of the axle is insulated as they are on 2-rail trains, then you won't get a short.

Guess I assumed plastic trucks have plastic wheel like mine

That’s very interesting. All of my passenger cars have had or have metal trucks and metal wheels. All of my freight cars have sprung metal trucks and metal wheels.

I have never heard of and have never seen plastic wheels on O-scale trains, regardless of manufacturer.

@Yellowstone Special posted:

That’s very interesting. All of my passenger cars have had or have metal trucks and metal wheels. All of my freight cars have sprung metal trucks and metal wheels.

I have never heard of and have never seen plastic wheels on O-scale trains, regardless of manufacturer.

After the postwar period, Lionel started using plastic wheels on some of their rolling stock typically found in the lower-end train sets but also as separate sale items.  While this obviously would provide the advantage of not shorting out on the tracks if they derail or put on the track incorrectly with power applied, the downside is that they don't work with track-activated accessories and switches that use electrically insulated rails, and it also took some of the "heft" out of the already lightweight cars.

Typically you saw them on unpainted plastic rolling stock like the short 9" flatcars, 2-bay short hoppers, gondolas, and "scout" plug door boxcars and small (SP type) cabooses.  Metal wheels were retained for the higher-end rolling stock like the 11" quad hoppers, 6464-based boxcars, stock cars, reefer cars, 11" flat cars, bay window and porthole cabosses, etc.   Eventually (and wisely) Lionel finally started to phase out the plastic wheelsets for 3-rail during the LTI era.

@John Korling:

I was unaware. Thanks for the enlightenment, John.

I am thinking that MPC was the first to use Delrin for the truck/coupler assembly.  Early MPC also used a clone of the PW AAR truck but it had a crudely cast appearance and was a bit wider axle to axle designed to fit the new fast angle wheels with needle point axles.  The footprint was similar to the Symington Wayne coupler that replaced it. 

@Yellowstone Special posted:

I have never heard of and have never seen plastic wheels on O-scale trains, regardless of manufacturer.

Very common... Kris, KMT/AMT, Williams, and here is a Lionel 9140:

@ADCX Rob posted:

Very common... Kris, KMT/AMT, Williams, and here is a Lionel 9140:

So, all with plastic wheels? I’ve seen some plastic truck sides, but not plastic wheels. That’s amazing. 🤔

@Yellowstone Special posted:

So, all with plastic wheels? I’ve seen some plastic truck sides, but not plastic wheels. That’s amazing. 🤔

Yes, plastic wheels. I have many, including Lionel, Kris, & Williams.

@Yellowstone Special posted:

So, all with plastic wheels? I’ve seen some plastic truck sides, but not plastic wheels. That’s amazing. 🤔

Plastic wheels were very common in the 1970's on low end MPC.

Stu