Are Lionel front truck wheels interchangeable?

Johnny,

    It looks to me as though they just need a cleaning. Here is the part number if I am wrong. 

Bill

Thanks Bill that's perfect. I thought it would be just the wheels, but that's probably better because sets are badly worn.

Those wheels don't need replacing - they are just incredibly dirty.

take a small flat blade screwdriver and that gunk should chip right off.

Yep, looks like "electro-gunk" to me! Thick enough to chip the big stuff off, clean the last bits carefully with alcohol (care around paint & plastic), and lots, and lots, of q-tips. All wheels should be cleaned. And it wont be just the loco, cars too. Clean them all. And the inside edges & tops of your track(outside rails) On some stock it will be every wheel. Others only one will do the gunk collection. Its strange. If anything begins jumping the track, that is the first thing I check. 

Looks like carbon buildup from electrical contact with the rails. It needs a good cleaning. Another way is to use a wire wheel attachment on a dremel tool. let the wire wheel spin the train wheels while cleaning. All the carbon will be taken off and the wheels left clean. Make sure you wear safety goggles. the carbon will be thrown by the dremel and can cause eye damage. Also, if possible do it away from the layout and be careful about any wire strands that can get into the engine or on the track and short things out. I usually don't recommend wire brush to clean trains but the wheels look pretty bad. 

Sometimes, but not always.  Lionel has made many locos over the course of many decades so I would say in general, no: don't assume they will be.  But in a lot of cases the front and even the rear trucks and wheels can be interchanged, etc.  

I have done this in particular among the Lionchief Plus locos, removing and changing trucks for other Lionel trucks-I bashed two of my steamers, Hudson and Pacific, into acceptable (to me, at least) scale models of smaller, older locos.  I also played "truck games" with a Legacy Mogul I did not like and changed around alot, actually adding a small rear truck to make it a 2-6-2, etc.  About 25% of the time the new truck(s) just bolt right on.  About 50% of the time, some slight modification, washer as spacers, etc., has to be done.  About 25% of the time it requires more work, perhaps enough that a person might give up.

Wow, "electro-gunk” ok well it looks worn to me, but my eyes aren’t what they used to be.  I’m on my way to work now, so I guess I’ll have to pull out my magnifying glasses and start picking a way at it when I get home. Thanks for all the responses.

I don't think you will need a magnifying glass.

I just hold a flat edged knife against the wheel and rotate it by hand. Since the wheels are fixed to the axle, you can turn them by the wheel that isn't being cleaned.
The gunk usually comes off in strips. There is often a little left behind. I remove the remainder with a qtip dipped in mineral spirits. First the wet end, let it work for a few moments, then mop up the gunk with the dry end.

We all seem to have our own techniques.

Lay it in a few soft raggy towels, or hold it nice, don't break/bend things on top!. If you don't have a cradle. Some foam/bubble wrap/towel lined miter boxes & scrap wood works fairly well. Drying any traction tires of solvents asap would probably do wonders for its life span.

Its likely time to add some lube! Small oil drops, push grease on gears, work it in, let it sit on towels 24hr, wipe. etc. & Checking, and "dusting" of brushes, and armature contact "cracks" on non-can motors.

Definitely not worn, just a bunch of gunk caked on the wheels.  Not unusual.  I clean the wheelsets on mine up in a similar manner to C.W. Burfle above.

This can happen on rolling stock too.  With a reasonably steady hand you could clean it off with a Dremel with a fine wire brush attachment on it too, but in the case of the locomotive you may want to take the truck assembly off first.

You may think you are scoring the wheels deeply at first, its only the gunk.

There is never an end to wheel cleaning.  With the engine or car upside down, I like to cut a paper towel about half way through and slide it in between the truck and the engine or car body. Keeps the gunk and solvents off and out of other things.  If you use a wire wheel, which I do, protect your eyes. 

Well I guess you are all correct it is black disgusting dirt and I am just in shock because I just cleaned the track a month ago, but didn't pay much attention to the wheels. I just don't know where the black stuff came from and wonder if maybe it has something to with only powering one side of the Realtrax

It was a little to late though because I already ordered the new wheels that Bill posted. I might go ahead and use the new wheels anyway because as Ii was turning the wheel, I noticed that one had a bent axle I think. The wheel turns a little wobbly.

So I guess I'm going to have to clean the wheels of the 20 box cars behind it as well.

Sometimes its years, sometimes it seems to happen overnight. Some kind of magnetic "magic" It seems to attract everything...when it feels like it.

This gunk is caused by several factors; mostly from the residue from smoke fluid vapors settling on the track and mixing with dirt (dust).  Also can be from lubricating oil  from the engine (especially if too generous amount of lube/oil was applied to the engine's moving parts) & dirt, sometimes a little of all the above.

If you cut down or eliminate the use of the smoke units altogether, you may find that your track will stay cleaner much longer.

Well after all that I ended up with the wrong wheels. I got a single axle instead of a double axle from Lionel. What a waist of money and the shipping was more than the part.