EMD F7A Problem

[wb2002]

A few years ago when entering this hobby and while at a train show, I purchased 3 F7A's and F7B's locomotives. I ran 2 of each about a couple of months and had to move and postponed the hobby. I have now retired, moved, and restarting the hobby again. While trying out an F7A, it started to move but then stopped moving and only making noise when signaled to go forward or reverse (like in neutral). I discovered that the coupler on the worm gear shaft is slipping. It is the plastic receptacle that is attached to the worm gear shaft. I hope I am making this clear. There is another problem and that is the "Instruction Paper" included with the loco. The parts diagram and picture does not match the actual parts. It lists motor screw holders and motor fasteners that do not match what is actually there. The motor support I actually have is a 1 piece unit with screw holders built on. I also need another one of these since 1 of the screw holder portion broke off. I am not sure how to order or obtain part information for repairs.

Please help . . . . .

wb2002

[sd24b]

A few years ago when entering this hobby and while at a train show, I purchased 3 F7A's and F7B's locomotives. I ran 2 of each about a couple of months and had to move and postponed the hobby. I have now retired, moved, and restarting the hobby again. While trying out an F7A, it started to move but then stopped moving and only making noise when signaled to go forward or reverse (like in neutral). I discovered that the coupler on the worm gear shaft is slipping. It is the plastic receptacle that is attached to the worm gear shaft. I hope I am making this clear. There is another problem and that is the "Instruction Paper" included with the loco. The parts diagram and picture does not match the actual parts. It lists motor screw holders and motor fasteners that do not match what is actually there. The motor support I actually have is a 1 piece unit with screw holders built on. I also need another one of these since 1 of the screw holder portion broke off. I am not sure how to order or obtain part information for repairs.

Please help . . . . .

wb2002

do you know the maker?  Other option would be to check out NorthWest Shortline's coupllings.  Phil

[Doneldon]

wb-

Welcome back. You'll find lots of new things in our hobby and I'm certain you'll be glad you've rejoined us.

About you locos. Do the other models operate satisfactorily other than needing a little cleaning up and lubricating after the long layoff? If so, you can use them as standards by which you can judge the problem child.

We will have better answers for you if you give us some more information like the loco's manufacturer, model number if you know it and approximate age. Just about every model railroading company that ever made a locomotive made a version of the F-units, and there are significant differences between them. Knowing exactly what you have will permit us to be more helpful.

Once again, welcome back.

                                               -- D

[bobwrgt]

For the coupler repair on worm shaft. There is a single screw at the top of the truck assembly holding it in. Take that screw out and the truck should just drop down and out.  With it separated from the drive shaft you can put a drop of super glue inside the u joint where the worn gear shaft  comes thru inside. You can also put a drop on the outside but don't let it get on the shaft part that goes to the worm housing. I have done this several times and they hold good after repair.
You don't have to remove the motor to repair anything unless you are replacing the motor. Just drop the trucks. The motor should be a tight fit so the one screw should hold it. You could put it back in and use the one screw. Hold it down tight and put a drop of glue in the hoe for the missing screw.
When you put the truck back in don't over tighten the single screw. the truck must move free to swing and the screw might go thru far enough to hit the worm shaft and coupling.
For replacement parts you will have to call Bachmann service and explain what you need.

Bob

[wb2002]

Thanks for all responses and I misunderstood some things about this forum. I thought this forum was dedicated to Bachmann products only. The item I was referring is a Bachmann Plus, EMD F7A (Union Pacific) #1470, Item No. 11204.

I have the trucks out already and was also thinking about using super glue to hold the plastic piece that the drive shaft fits into. Also, the motor support is pretty secure with the 1 screw.  I don't think I will have any problems. I had already converted the units using Digitrax DH140 decoders long ago.

Again, Thanks

wb2002

[sd24b]

Thanks for all responses and I misunderstood some things about this forum. I thought this forum was dedicated to Bachmann products only. The item I was referring is a Bachmann Plus, EMD F7A (Union Pacific) #1470, Item No. 11204.

I have the trucks out already and was also thinking about using super glue to hold the plastic piece that the drive shaft fits into. Also, the motor support is pretty secure with the 1 screw.  I don't think I will have any problems. I had already converted the units using Digitrax DH140 decoders long ago.

Again, Thanks

wb2002

WB    I don't think ACC will hold up under the pressure, although you can try it.  Have you tried Bachmann?  Phil

[DougInCal]

Rather than starting a new topic, I felt that my question was germain to this thread.

I pulled my HO trains out after about an 8 year hiatus.  The two Walther GP's seem to going okay (albeit very noisy), but my Bachmann F7A (item # 60102) has started to just sit and "spin its wheels."  I thought that I was not getting the trucks on the track, but based on the symptoms that I have seen in this thread, I believe that I have the same problem.  It sounds like the loco is "grinding" internally.

I "goggled" around for schematics and info, etc, but haven't found much help.  I would like a little input as to how to tear apart this loco, before I in fact, tear apart this loco.  Also, does my problem seem to be the same as what the originator of this thread had experienced? 

[Len]

See if the fuel tank pull off. If it does, there should be two screws hidden underneath that hold the shell on.

Len