Drive Wheel Gauging

According to the Lionel service manual, the distance from the outside of the flanges at the thread is 1.265".  Or you can measure between the inside of the flanges which would be 1.095".  Generally, when the axle is even with the hole in the wheel (and not protruding), the gauge should be close to those dimensions.

@Jon G--

Jon, which year of the Service Manual and under which numbered locomotive section (ie, for which loco by its number) is your data found for 1.265" over outside of flanges at tread, corresponding to 1.095" back to back of flanges?  This data is interesting to me as this gives a resultant flange thickness of 0.085" at the tread, a figure which could not be gotten from the data in the Greenberg set of service pages from postwar-- which is very representative but not by any means a complete record.

What I did find in the Greenberg copies was a back to back of flanges dimension of 1.10" for another road model of the diesel switcher with the cast frame and non-intergral Pullmor motor.  The switcher was 6220, IIRC-- but the important thing is that this engine was for 0-27 sets and track (hence the 4th digit "0").  It is not widely known, and for the benefit of OGR readers I will mention it, that the gauge of 0-27 track is effectively about 0.03" wider than that of "O" gauge track.

I'll also mention for the readers that my typing of 1.10" is intended; it appears that way in the 6220 page.  This 1.10" is the same as 1.100" (ie, to a thousandth), but giving it to the repairman to the hundredth indicates that a lesser precision will suffice.  (The actual precision associated with each is not standardized, but is usually agreed between the designer and the machinist.)  In this case, the repairman is instructed to make a gage of width 1.10" for re-gauging these 6220 wheels as necessary.  (One could interpret this to mean not less than 1.095" nor more than 1.105".)  (You will realize that in China the smaller dimension will save on the material that goes into the axle,)

In the era of these 6220 instructions, Lionel was having trouble with this truck derailing at the frog on the curve of the 0-27 remote control switches.  This truck was used in the 2023 UP Alco diesels of the 1950 0-27 set which I had received, and in 1951, -2,and -3 I received each year a pair of the remote switches.  Each year  had a different frog design, but the derailments were never satisfactorily resolved for me.  (I just realized that I have never checked the wheel gage on the engine.)

If you notice the axle bore bosses on the engine trucks (at least on the F-3s, which were generally "O" engines  in this same era), you'll notice that the wheelsets can be gaged in to 1.07".  At the time Ross Switches suggested a need for some standards in this area, OGR set up a dedicated forum for about a year.  I contributed some measurements from various engines as made.  I also made a considerable study of the solid frog/guard rail situation on the split rail switches, only a portion of which I had posted prior to the closing of the forum.  I did limit the work to the "O" track and Lionel engines intended for it, including only the Lionel O-72 switches.

What I did discover is that the short wheel base, small wheel Lionel diesel trucks (ie, the 2-axle F-3 or GP-7/9 trucks) should be gaged in to 1.07", while the longer wheel base, larger steam drivers were properly gaged at 1.10".  I used the full size 1:48 Hudsons with 4-6-4 wheel arrangements in this matter.  The problem which had arisen in the "modern" era is that the two-axle diesels trucks intended for "O" track were also, incorrectly, being gaged at 1.10" for the most part.  This also caused problems in their gear trains.

What happens is the steam drivers need a wide flangeway at the curved-side guard rail in the switches, compared to smaller wheel on short wheelbase.  Unless the short wheel base diesels are gaged in to the smaller 1.07" gage, the powered wheels may climb the frog point,* although the Lionel O-72s may have some widening of the track gauge at the frog to reduce this problem.  (I either did not have any, or did not check O-31 switches at this time.  The Lionel O-72s were Chinese production, although I think the track bases remained unchanged.)  *Note:  A powered wheel climbing the frog may have been more noticeable with the 1950 Alco for me, as I generally ran it with the single-motored power unit pushing the dummy unit (per the recommendation).

--Frank M

It was at the front of the Greenberg service manual for Lionel trains and was mainly intended for steam wheels, but the NOS trucks I have are the measurements in my first post.  The 1.265 dimension was made using a pair of calipers on the thread of the wheel with the points of the caliper touching the bottom of the flange.  My experience is that the gauging on tinplate wheels is not as critical as scale O gauge wheels.  I set many more wheelsets at MTH to please the scale users than tinplate.  Look at the prewar wheels. The gauging is all over place and in most cases they work fine on tinplate track and switches.

The wheels and axles used on the 602 come from a family of diesels starting with the 622 and the 2333.  All of these wheels have flanges that are 0.080" thick.  These numbers are based on Lionel drawings from the late 1940s and 1950s. The axles used in the family of locos are 1.616"  long.   On the 2333/2343 wheels the width of the rim is 0.281" wide. The outside hub is 0.047" inboard of the outboard edge of the rim.   Using these dimensions, if wheels are pressed even with the ends of the axles, the gauge will be 1.308".  Most axles have a shoulder at the inboard edge of the wheel seat.  The length across these shoulders is 1.096".   The inboard hub face is 0.010" inboard of the back face of the rim.  If the wheels are pressed up against the shoulders the gauge will be 1.256".   To get the gauge of 1.265 would require that the wheels be pressed using additional tooling.   Given the number of wheel sets that Lionel was making, custom tooling is reasonable and expected.  

The gauge point on postwar Lionel wheel sets is where the flange intersects the tread.  This is different than the track gauge which is measured at the narrowest point.  Since the rail shape is a tube, the narrowest point is some distance below the railhead where the wheel tread runs.  To get the back to back distance for this family of diesels, subtract the flange thickness, doubled, from the gauge. 

Jon G posted:

It was at the front of the Greenberg service manual for Lionel trains and was mainly intended for steam wheels, but the NOS trucks I have are the measurements in my first post.  The 1.265 dimension was made using a pair of calipers on the thread of the wheel with the points of the caliper touching the bottom of the flange.  My experience is that the gauging on tinplate wheels is not as critical as scale O gauge wheels.  I set many more wheelsets at MTH to please the scale users than tinplate.  Look at the prewar wheels. The gauging is all over place and in most cases they work fine on tinplate track and switches.

 

Thanks Jon G, I just found that info in my copy. I measured my wheels and there appears to be a large amount of wobble, with measurements ranging from 1.200 to 1.402 on one axle, similar on the other. Hopefully I can do a better job when putting them back on. So would you suggest removing the gear wheel or the non-gear wheel? Or in my case, removing the wheel with the most wobble, which on both axles is the non-gear wheel?

I generally remove the non-geared wheel, if you can get the puller behind the flange.  This way when you press the wheels on the geared wheel is meshing with the idler so it won't get jammed if it is pressed  into the idler.  In your case, the axle is bent so I would try side loading the wheel in a press or vise on the "high side" to straighten it.