American flyer 346 revese unit in rear of engine

There are 2 types of reverse units that could be on the engine.  A two step and a four step.  Do you know which type is on your engine?

The poster says it is in the rear of the engine, so sounds  like it is the forerunner of the later two position unit. Not one of Gilbert’s better designs.

Without getting one of mine out, I seem to remember that one of the reasons that it doesn’t operate very well is because of the angle the reverse unit is mounted on the motor. Ideally it should be vertically mounted but it isn’t, memory tells me it is about 15-20 degrees off vertical. This hinders the armature from operating smoothly, especially when it wants to drop when the power is removed.

As an experiment lift the front of the engine about 20 degrees and see if it operates any better when you cycle it under power.

Gilbert put a 4 step reversing unit in the early 346 and later 343 and it didn't work smoothly so the later changed it to the 2 step reverse unit.  Both were mounted on the back of the motor.  If you have a 4 step unit don't expect it ever to work pretty good.  A two step can be repaired but it too is hard to work on.  Replacement of the two step is what I commonly do.  

If you have an engine with a 2 step compare it with the one on the 346 so you know what you have.  If you have a 4 step and are not an expert with repairs maybe a new electronic E unit would be a good option.

Thanks for the input,  UKAFLYer & Roundhouse Bill  I believe its a 4 step unit. I did try to raise the front of the engine to try a different angle,  no change.  If I find a 2 step unit can I  replace the 4 step without any changes 

The plastic brush holder which is the back of the motor must be changed. An easy way is to find a cheap 5digit Atlantic and transfer the brush holder and 2 position reverse unit.

FWIW, I'd take a look at the electronic e-units that folks like Dallee offer (with whom I have no relationship other than as a customer).  For less than $50 you can get a 4 amp unit that handles either AC or DC.  I haven't replace the e-unit on a 346 (but have on other locos where the e-unit is in the tender), but you should be able to either install it in the tender or perhaps even under the boiler shell in front of the motor.  It also has the advantage that you can power an LED headlight from the board and it can be set to always start in the forward direction from a powered off position (e.g., block control).  Dallee is at Dallee.com.  If you plan on using the loco a lot - especially for switching - I think replacing the old electromechanical e-unit is worthwhile.

The 4-step on motor reverse unit relies on a light spring to drop the pawl. It has to be adjusted "just right" so that the lever goes up when the power is turned on, yet drops when the power is off. Yes, the unit is a bit "picky" on how it's treated to work.

Some of us like the  challenge of making the original stuff work, and some just like to keep everything "ACG."

David -- I agree that making some of the old 'stuff' work is fun and satisfying - but in some cases, I've learned to know a PITA when I see one, and some of the ACG e-units (I know, that's a Lionel term...) are not worth the powder it would take to blow them up.

- Rich

I went and got my 346 off the shelf and lubed it up to give it a spin.  I actually have every one of the 0-8-0's except the DC versions.  Boy was I pleased to here its whistle blow.  The 346 is the only version that was so equipped.  I will have to rebuild the smoke unit, but other than that is ran well. 

There is one thing we haven't mentioned.  The reverse unit does have a switch to lock it in one direction or in neutral.  It is able to be seen on one side of the unit.  You pull it back to lock it or forward so it will cycle.

Mine's reverse unit worked OK.  Every once and a while I tapped on the cab to get it to go to the next position.  But, I do that with a lot of the original 4 step reverse units on my Flyer engines. 

Rich, True; but I think this unit gets a bad rap, partly because it IS different and few parts are available, and partly because it isn't as robust as the "standard" unit. But then I think the two-step units are a PITA, although I do work on them, when I have to.  Now the 314AW whistle relay---well. . . . . . do you think it will rain tonight?

Boy, I wish it would rain tonight -- we here in Northern CA are looking into the teeth of another potentially disastrous fall fire season...

Were you able to resolve the issue with the sticky e-unit?  Are you able to watch the unit as it goes through its cycles?  The pickup that engages the drum teeth may be catching on the drum as it tries to fall back.  If it is catching, you can ever so gently, bend it to allow it to move freely.  If not that  is the drum in good shape, especially the teeth?

I have disassembled my 346 with the 4-step reverser and can't figure out the wiring diagram from the AF manual.  Would anyone have a good wiring diagram or could take pictures of this to help me?  thanx!

I found this on OGR Forum.  I will try to attach it.

If it doesn't work call me 919 840-8618.

Jim cummings

Jim, thank you so much!!!!  Just before you sent this, I was thinking they may have made the chassis hot!  It also explains why one of the screw plates is metal and the other is an insulator.  Thanks again!  chuck