REPAIR HELP

IMHO, I'd leave it alone, with the following thoughts/caveats...

1. If you put some material on the inside of the body shell across the break, it may no longer fit the chassis properly.  My guess is that there is a chassis flange which fits snug to the inside of the body to which this screw is attached.  If you add plastic to the inside surface, you may add new stress to the body at this point when it's fastened to the chassis.

2. This sort of screw hole stress/breakage is common to several engines having this sort of attachment of a plastic body to the chassis.   I believe a contributing factor is overtightening of the screw.  I've watched people repairing these sort of products.  For some reason they must believe that incredible forces will be in play through normal use to pull apart the body and chassis, so they'd better wrench the screw down as tightly as possible!!  But, why?   

3.  Contributing to the 2nd point, above, is a manufacturer's use of a flat-head screw at a weak point in the body casting.  The underside of a flat-head screw is conical.  That will exert a wedge force to the hole in which it's located.  If there's sufficient material around the hole, it can absorb more fastening torque without breaking.  But if there's insufficient material in any direction around the hole...as with your part in question...it's going to be the first to yield to excessive torque.  If there was no other location for the body screw in the product design, a round-head screw...or similar one that has a flat, non-conical surface beneath the screw head would probably have been a better choice.  Just MHO, of course.

But that's just my opinion. 

KD

i agree the shell stays on with whats left. looking at it im thinking there is enough space to glue in a piece of heavy mylar sheet. what im thinking about the crack is just clamping it with a bit of glue but i wonder about seepage marring the outside as it it its hardly noticable ,..  thanks i'm still thinking about it but in no hurry   joe

How about cutting a perfect square or rectangle of plastic, the same thickness as the shell, and carefully removing the exact same size of plastic from the shell. Then glue in what the old time furniture and boat repairmen called a "dutchman", wait for the glue to set, and carefully, starting with a tiny drill bit, drill out the hole using successively bigger bits until the hole is the right size. If you plan to use the original screw, you'll need to countersink the new hole.

To get really fancy, chamfer the edges of the hole and of the insert piece, to ensure that the insert lines up and doesn't "squirt out" when gluing it into the shell.

https://en.wikipedia.org/wiki/Dutchman_(repair)

I have done this in my other hobby of restoring the plastic shells of old telephones. The kind where the original shell had a "mousehole" where the cord came out, and the well-meaning idiots at the phone company rebuild centers punched a rectangular hole to upgrade the phone to allow the installation of a modular jack.

If you must fill the crack, JB-Weld, you can shape it to the thickness and shape of the missing piece.  A little touchup and you're good to do.

Also, there is a little brass ferrule that is used in these to take the force of the screw and spread it around the hole without expanding it and cracking it.  No, I don't know the part number, but I'll bet folks like Henning's Trains or Jeff at The Train Tender will have them.

john that might be the best way to go ferrule and replacement screw for it . i'll look into it.  thanks again 

I have made that repair and done as gunrunnerJohn suggested.I filled hole/crack with JB Weld sanded it even.Redrilled screw hole but used a standard screw with same thread and a washer not a conical screw.Not a collector piece but still a runner...

GRJ has the right idea.

My only suggestion would be that before you start to fill the area, that you cut a thin piece of mylar or styrene (maybe .020 - .040 thick) and wide enough to extend past the hole sideways by about 1/4" on either side of the damage and CA glue that piece in place on the underside before you start filling the area.

That will give you a good backing on which the filling compound can lay and give you an easier and stronger repair.

You need to use pretty thin Styrene or you'll cause fit issues, but that's not a bad idea if it fits.  I wouldn't go any thicker than .02".

So just to give you guys an update i used sheet aluminum as a backer i guess about 1/16". epoxied it in. drilled the hole thru the aluminum. still have enough space between the frame and shell. found a perfect fit pan head screw #2 x 5/16. its a lionel screw but i won't tell anyone. there is enough meat left on the plastic to hold the eyelet so i may just glue it and not fill the missing plastic at all the eyelet will cover most of it anyway.  still hunting for the eyelet though 1/8" barrel x 1/4. i found a couple but got to search locally as 10 bucks shipping for a 50 cent part doesn't cut it. have jeff at the train tender working on it for me. waiting to hear back. anyway the project is about complete outside of fitting the eyelet lengthwise when i get it. appreciate all the input.  joee

Another suggestion, although a little late. I did this on an PW FM Trainmaster. The shell had a few light scuff marks, etc, so collector value wasn’t there hence the method of repair. Anyway, these FM’s are notorious for screw hole issues. The other end had a hairline crack but complete other then that. The damaged, piece missing end: I used a piece of styrene, the same thickness of the shell, cleaned up the crack and fitted the styrene in the remaining opening. Having completed that with a nice clean fit, I used clear very thin styrene, only because that’s what I had available and used as a backer on both screw holes. The idea was to lengthen the “inside” so that it fit the chassis properly. Finally, I used a Irwin clamp, any clamp will work so long as you can invert it such that it can stretch the shell out. The shell had curved slightly inward on both ends. Anyway, a little outward pressure was applied, using the clamp and then light use of a heat gun to soften the shell plastic. Doing this takes practice, not to much heat to misform/damage the plastic but just enough to soften it. This step was repeated multiple times over a 2 week period, mostly because I was in no hurry, plus I had other projects to work on. I think it turned out pretty good. (Sorry, no pics). It just so happened I had all the cars needed except two (and easy to find) to make up a Thunderbird set.

Steve

will keep that in mind  thanks