Lionel PRR F7s Overhaul (TMCC F7 6-24584)

Recently I had both of the issues you described.  One on a Lionel AC6000 with the coupler.   I found that one of the coupler wires had a small cut in it and was randomly grounding on the frame.  Regarding the issue of power loss on switches, make sure that the wire to the rollers is solidly attached.   I had one which looked like it was and had shrink wrap on it but the wire itself was not attached to the lug.

Marty

Solved the power outage issue.  Cleaned the wheels.  Duh.  😂

Next, follow Marty's advice and search for shorts on the electro coupler wires.

... Also duh 2, is that there are 4 rollers on these, and it was having issues not only on switches  Anyway, it's crawling around the layout with no power losses now. 

Ordered some 1 microfarad 50V nonpolarized capacitors, which is what my online research discovered as the specs for the capacitor that is needed across the electrocoupler leads. 

Also, the smoke unit in the nonpowered A unit pulses periodically which I read is a feature not a problem 🤔😅  If anyone has any helpful comments regarding this please let me know   Thanks!

pennsy484 posted:

Ordered some 1 microfarad 50V nonpolarized capacitors, which is what my online research discovered as the specs for the capacitor that is needed across the electrocoupler leads. 

The way to test this is:

Disconnect the wires to the coupler.

If the coupler still opens spuriously, then the problem is mechanical within the coupler. Maybe a weak spring.

If the coupler no longer opens spuriously with the wires disconnected, then it is an electrical issue and requires the capacitor across the coupler leads.

Thank you Roy.  Definitely electronic issue, but I will check when I get the caps and disconnect the leads  

Another thing that bugs me about these are that the green color is too light.   Way lighter than the Lionel Legacy GP7's and any PRR diesel I have ever seen (models,opreserved prototypes, or photos I have seen).  Note the colors in the pictures below. 1st is the Lionel F7 at issue, 2nd is an MTH PRR F7, 3rd is a PRR GP9 at the RR Museum of PA, and 4th is an old picture of a PRR F7 in service. 

Some other comparison shots:

MTH left Lionel Right 

I had been thinking for a long time about darkening the paint somehow.  I didn't want to repaint because I didn't want to redo all the decals.  So I decided to make a wash using Dr. Ben's black pigment mixed lightly into 70% alcohol.  I applied with a brush and then cleaned off the decals.  They didn't come completely clean, but I think it serves well as weathering.  

Now, I really don't want it to look too weathered, and the idea here is to darken the color (while the light weathering side effect is welcome), but coating with Krylon Matte Finish disipated the brush strokes, evened it all out and sealed the wash.

I am posting because I am really actually surprised how well this turned out.  I didn't know if a wash could be made to not be blotchy or if it would just stick in crevices, or on the other hand if it would completely cover the green rather than resulting in a dark (Brunswick) green, but it works well I think.  Check it out:

Finished product:

Original color powered A on left, darkened A on right:

MTH left, darkened Lionel right:

MTH (L), darkened Lionel (C), untreated Lionel (R). 

The two Lionel A units:

I want to make the pilot a fixed pilot. I recall someone posting about doing that, including material for making a shim. Maybe it was Norm C.? Does anyone know the thread? I couldn't find it   Thank you. 

I believe the first step was to lower the shell a bit. Not sure if it was easy as the F3's were.

https://ogrforum.ogaugerr.com/.../lowering-lionel-f3s

Also note how easy it is to close up the coupler gap...

Here is a thread on how a Weaver dummy coupler can me manipulated to close the gap

https://ogrforum.ogaugerr.com/...set-of-lionel-sharks

J Daddy posted:

I believe the first step was to lower the shell a bit. Not sure if it was easy as the F3's were.

https://ogrforum.ogaugerr.com/.../lowering-lionel-f3s

 

Also note how easy it is to close up the coupler gap...

 

Here is a thread on how a Weaver dummy coupler can me manipulated to close the gap

https://ogrforum.ogaugerr.com/...set-of-lionel-sharks

 

YES! Thank you!  I noticed how the trucks are mounted but hadn't thought of this idea. Brilliant!  Going to try it! 

How about the close coupling? Do you have a thread for that too? 

Jeff,

Nice work.  I'm definitely taking notes!

Jeff -

reference the second link for close coupling. I cut down a dummy Weaver coupler and drilled through it to bring the units closer together.

The only down fall of the F3s  is they have magnatraction and seem to pick up any small metal particles and deposit them right in the gears... I am not sure about the F7s...

I finished up the color darkening. For the powered A unit I used an airbrush to apply the Dr. Ben's black powder (diluted in 70% alcohol, using a fine tip, which I figured would give a nice even distribution of the powder.

For reference here it is again in original color:

And after:

Intermediate steps:

Dried airbrushed Dr. BEN'S :

Used microbrush with 70% alcohol to clean off the decals:

And sprayed with Krylon Matte Finish:

Fixing the pilots is a matter of making a spacer to fit/fill the gap, and another spacer(s) to adjust the height of the couplers. These are MTH FTs but the Lionel F7s were done the same way.

MTH F units with the same treatment

Laidoffsick posted:

Fixing the pilots is a matter of making a spacer to fit/fill the gap, and another spacer(s) to adjust the height of the couplers. These are MTH FTs but the Lionel F7s were done the same way.

MTH F units with the same treatment

 

Very nice. Does someone make the spacers, or do we have to make them ourselves?

If someone makes them, then whom, please?

I made the spacers from styrene.

LOS:  What is the thickness of the styrene and what was your source for it?  I have several pilot fixing projects in the hopper (several MTH E6, Lionel F3 & MTH DL-109) but have not been able to find a source for "thick" stuff.  As always, your advice is highly valued.

The TMCC F3s and Legacy F7s are different, as the high water F7s need a little more lowering, and hence the trimming of the screw posts on the inside of the body to make the 

I haven’t heard if the new F7s need to be lowered as much, but I don’t believe so.  Lowering the heights of these units, as well as most of the Legacy diesels, brings them to scale height as measured from the rail tops and this’ll negate the need for a spacer. 

If you search, there’s more details on here on lowering both F3s (page linked above) and the high water F7s.  It brings them to the same heights as the Atlas F units.

Here’s the TMCC F3A and a high water F7B for comparison. 

Thanks!

-Mario