Where can one find a 5 x 8 sheet of wood?

One more thought that I will put out there before going the route of using the caulk.

     -If I do, that then I am treating the symptom (vibration) as opposed to treating the condition that is causing the vibration. 

Anyone have thoughts as to what is causing the vibration in the first place, that is then being heard through the shell bc of vibration?  And better question, how to go about solving that condition?

Thanks all.

Yes it does Jonathan.  That is the best word I have used to decribe it.  Buzz, as opposed to a "growl" or "clunk"....

Yes D, it does run quieter w/the shell off.  And at slow crawl speeds, very quiet.  Thank you for the suggestion.  In doing that, would I ever be able to take the shell off again?

Stephen-I am running it DC.  I did wonder if it is the motor or flywheels, and have watched the flywheels turn with the shell off.  They don't hit the frame or appear to wobble.  The more RPMs, the motor turns, the more you can see both dog bones go from running truly straight to having a little more of an "elliptical orbit" to them as they turn.  The motor though looks like it is level and definitely is not loose.  I have taken  the motor out and run it by itself.  The higher RPMs, the more vibration it makes; but there is nothing visible that the motor does that would indicate why it is vibrating more.

The faster the speed, the more a "buzz" noise is produced by my loco.  It is lubed and oiled, so it is not a dry problem.  I have also put black electrical tape where ever I can between the shell and frame in a effort to buffer vibration between the frame and shell, but to little avail.  I have run it repeatedly with the the shell off to watch the mechanics and everything looks fine-no wobble, no binding, etc.  Whatever is causing the noise, certainly appears to be resonating through the shell.

Thanks for the help.

I was 5 and for Christmas got an AHM set that contained a Pennsy Alco RS 2 or 3 (at the time I did not know or care-was just excited to get a train set!) And the following cars: The red white and blue Bangor/Maine box car, a yellow cattle car, a Pennsy cabose and Rhode Island or Rock Island gondola. At first it was a figure 8 on a piece of Masonite.  My father also gave me use of a couple of Gilbert cars: a B & 0 box car, Gulf tanker and black B & 0 gondola.  He also gave me a B & 0 steamer that had a tender attached.  No idea what kind of steamer or maker, although my dad seems to think it was a Mantua.  The cattle car never seemed to track well and it always seemed to be much "higher" than the other cars.  When I was between 8 and 10, I grew to hate the Alco, bc it could not pull squat, even on a level surface.  It and the steamer died (too many moving parts on the steamer for a young fella).  They got replaced with an Athearn Blue Box Chesapeake and Ohio F7 "super weight"  which I still have today, after recently replacing a truck (the kind with the metal side plates) and doing everything short of the Pearl Drops on the Athearn "update" routine. The F7 is a "beast" and can pull a ton of cars. 
I still have the Bangor/Maine, all the other AHM cars took headers off the 4 x 8 particle board the layout was later on when we moved to the suburbs.  I do still have some parts from them.  The Gilbert gondola disappeared as well but I recently put Kadees on the Gilbert B & O and Gulf Tanker.  They still have springs on their trucks.  Over time, I also came by my father's Atlas snap switches and other Atlas track to supplement the AHM track.  Brass of course, but stil in use today, with my son.   In fact, some of the switches lasted until just recently.  They came apart bc the plastic was breaking down.  I also just recently replaced the transformer he gave me to use, a big green thing, made in W. Germany that had forward and reverse controlled by a single dial.  12:00 position was off and to the left and right were forward and reverse.  It was still working; just not as efficient as more modern transformers.  Don't know what ever happened to the AHM transformer that came with the set I got for that Christmas.

Thanks.

Do you know where I can find the re motoring topic you mentioned, in other sections of this forum?

And btw, I think we both know that to scale in the real world, does not always translate to true scaled features in the HO world; at least not from what I have read about complaints about how Blue Box Athearns are too wide and how flawed their noses are on their models like the SD45.

Jward-do you mean in real life or HO life?

Thank you both for taking the time to send your replies.  The locomotive I bought for my son, is Bachmann's current Blue Box locomotive, FTA model.  It has a can motor w/o the flywheels.  The heart of my question is, can the shell from this model be placed on either a Bachmann Spectrum or a Bachmann Plus F7 or FTA chasis?

Thanks very much for the help.

Good Morning All

Does anyone know if I can replace the existing motor in the above referenced unit with the one sold on this site that is listed for the F7 model, that has the brass flywheels?  I ask bc I bought my son the above for Christmas and it runs great except for having a lot of trouble going up an AHM standard trestle  grade with more than 2 cars attached.  This is the only loco in our fleet that has this problem and in looking at the motor, I see it is just a can motor with no flywheels.  I have added all the extra weight I can and my thought was a flywheel motor would have more torque than the standard issued motor thay is in this loco.
Thank you for the help.

-Jim