McCoy wheels. WHAT IS NEEDED?

I would be very interested to hear others' comments or observations on this.  I am not a Lionel or McCoy "expert", what I am is a tinkerer, and find myself using various parts together on a project.  

My assumption has always been that before MEW, there was McCoy making clone drive wheels as replacements for Build-a-loco motors, so they had to be the same specs as original Lionel wheels.

I just went to the train room with my digital calipers and mic.

The drive axles in original prewar Lionel BAL motor mics  .180.   Within normal variation (.178 to .181) this is the same for: original drive axles in McCoy-built motors; and McCoy axles used in their car trucks; and Lionel 200 series car axles; and I also calipered the interior bore of McCoy drive wheels which is the same – all in the .178 to .181 range: some of these are used pieces, and some are unused NOS parts, which may account for the slight variations.

One thing I use a lot of are the Williams standard gauge dual-can-motor units, which have a larger diameter drive axle (.188) which means drilling out a set of drive wheels, which then will not fit back on anything else.  I mention this since the Williams motors came in reproductions of Lionel locomotives, and can frequently have McCoy drive wheels on them: McCoy drive wheels on the Williams motors will have been drilled out to a larger axle size, but I do not believe these represent stock McCoy wheels.

Of course Flyer and Ives wide gauge drive wheels are a different story.

But in my experience, the McCoy wheels were made as direct replacements for the Lionel BAL drive wheel and have the same bore.

You are right in that the boss on steam drive wheels is bored and tapped 6-32 thread on McCoy wheels rather than the larger 8-32 such as used on the Lionel 400e.  That allowed McCoy to use smaller rod spacers, which in turn allowed them to scale down the size of the side rods.  But did Lionel also have drive wheels tapped 6-32 for use on its smaller locos?  You would know that better than I would, but all my McCoy steamers have the 6-32 side rod threading.

It can get confusing: recently I was putting a set of drive wheels on a Standard Gauge conversion I was doing and was surprised to find that they were tapped 4-40 for the side rods... but that was probably because I was using O Gauge wheels ?

david

David,

          You are right in that the 385, 392 ,400 & 1835 wheels are all drilled and tapped for # 8:32 rod screws. The 384 & 390 are tapped for 4:36, not 4:40. The Lionel "O" and most all AF "O" are also tapped for 4:36 thread.  I have a Williams 381 w/ a dual can motor unit in it. I am going to 'pop' off the wheels and measure the axles (the wheels are bad anyway). I am now curious to see if they are .188 also.  That makes 2 positives for the McCoy 6:32 rod threads. I have found no 6:32 on Lionel pre war wheels that I can remember. If there is a need for the Williams wheels w/ .188 axle bore, I can furnish these also. 

          Thank you for your in-put.  Harry 

.