# 2338 goes faster foward than reverse?



## dbyll (Oct 22, 2011)

Well I,m back again and sure thank the Lord for this web site. I am restoring a 2338. Today I cleaned and lube the motor and gear box, including e unit. The engine runs well foward and reverse but is slower in reverse. Any suggestions would help.


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## Dave Sams (Nov 24, 2010)

I have a loco like that.

I polished the commutator contacts of the armature with an eraser. This is the copper part that the brushes contact.

After polishing the contact and assembling the motor and loco it ran better, but I just picked up the loco and turned it around on my layout so it would run better in the direction I wanted.


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## dbyll (Oct 22, 2011)

Thanks I will try that. I was also wondering on that gp7 if the track roller contacts are for each direction? Just a thought that came to me>


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## gunrunnerjohn (Nov 10, 2010)

I doubt it's the track rollers, my guess is something internal. I've seen locomotives that have gear wear, especially on the worm gear and it's mating gear in the truck. That will cause them to run slower in one direction than the other. Did you remove the armature and clean out all the old lube and freshly lubricate the worm gear drive?


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## Big Ed (Jun 16, 2009)

Do the brushes need replacing?
What kind of shape are they in?


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## servoguy (Jul 10, 2010)

And the lower armature bearing needs lube, also.

This is a common problem with these motors, and I have a couple that run better in one direction than the other. One of these days I will take one apart and discover what is going on. If you turn the wheels with your thumb, you will also discover that the motor may not even turn in one direction. I am sure it is a friction problem with the armature thrust bearings.


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## dbyll (Oct 22, 2011)

Thanks to all, I did lube and clean gearing. I did notice when turning the wheels the drive gear will push out a little. When turning the other way it does not. I may check into that and see if the nylon bushing is worn. The brushes look good. Once I figure this out I will then play with the horn. It keep this retired cop busy with my toy train set from 1955. I am still amazed everything is as good of shape. Lionel postwar sure were build great


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## dbyll (Oct 22, 2011)

I did check and the collection rollers both pick up the current from the center rail at both times. I bet I fine more dirt loose and will have to reclean motor. I can't get to the E unit to take it apart due to the fact it is riveted in place. Also what type of lube do you guys use on E units? Ive got a lot to learn but my younger years I repaired old clocks. Thanks again


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## servoguy (Jul 10, 2010)

When you do the horn, it is important to check all the electrical connections from the battery to the horn. The relay is a particular problem. The armature of the relay doesn't make good contact with the relay frame because it is just sitting on the frame, not electrically connected to it. What I have done in the past is solder a wire from the relay armature to the relay frame. Use a short piece of small braid as it need to be flexible. You can buy solder wick at Radio Shack which should work fine. Alternatively, get some strands of fine wire and solder about 12 strands between the armature and the frame. 

You can clean the relay contacts with some very fine sandpaper. I wouldn't clean them unless they don't work. Manually operate the relay with a battery installed and see if the horn tries to work.

The horn itself is often a problem. I have succeeded in making some of them work by rapping them with a screwdriver handle. The horn may also need adjustment. The horns are really poor quality. You might want to replace it.

You normally don't need to lube the E unit. Is yours working OK?

I have never seen one riveted in place, but that doesn't mean Lionel didn't do it.


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## gunrunnerjohn (Nov 10, 2010)

dbyll said:


> Thanks to all, I did lube and clean gearing. I did notice when turning the wheels the drive gear will push out a little. When turning the other way it does not. I may check into that and see if the nylon bushing is worn. The brushes look good. Once I figure this out I will then play with the horn. It keep this retired cop busy with my toy train set from 1955. I am still amazed everything is as good of shape. Lionel postwar sure were build great


It's normal for the drive gear to push out for one direction, when you're turning the other way, the torque is in the other direction.


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## servoguy (Jul 10, 2010)

Did you lube the armature bearings, particularly the thrust bearings?


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## dbyll (Oct 22, 2011)

gunrunner, thanks for that tip. I went back and looked at the brake down in Greenbergs of the 2338 and guess what? The ground spring is missing. If i'm right it goes between the motor and the top plate Could the be my problem? I would think in one direction the motor would torque upward and in the other direction torque downward.This is getting to be quite a good problem i'm having.


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## gunrunnerjohn (Nov 10, 2010)

Anything's possible, clearly you want to make that right, just to make sure it's not the issue. 

I've had locomotives that would do the same thing, and others that would be jerky in one direction and smooth in the other. In one case, I had to mix-n-match the two motors with the trucks to get smooth operation in both directions.


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## Dave Sams (Nov 24, 2010)

servoguy said:


> You normally don't need to lube the E unit. Is yours working OK?
> 
> QUOTE]
> 
> Normal is the word. This week I bought a 520. The E unit was very fussy until I put a little lightweight oil on the pawl. The pawl slides in slots on the side of the unit.


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## gunrunnerjohn (Nov 10, 2010)

I don't recommend lubing the plunger, but the pawl doesn't hurt, and may indeed help.


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## T-Man (May 16, 2008)

The big difference in forward and reverse is the connections in the e unit. Running may help the connections by flipping the drum around. Or you can rebuild it but if it works give it a little time. It is an old engine.

I can say I did not oil up the shaft of the motor on the Burlington with all the bearings. I just looked at the pages. Something more to do.

Sometime the pawl gets magnetised with magnetration engines.


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## plandis (Oct 5, 2011)

aren't those motors the ones with worm gear on the end of the motor shaft? 
mechanically speaking, worms always transfer torque more efficiently in one direction the the other. this is characteristic of the worm drive - (I think)

even with all things being equal ( clean, lubed, brush tension, electrical connection) all these things help but the worm drive is a worm drive. there will always be a slight difference in torque transfer.


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## servoguy (Jul 10, 2010)

I don't know of any reason a worm drive should work better in one direction than the other.


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## gunrunnerjohn (Nov 10, 2010)

The only reason I can think is that the thrust is in the opposite direction. I've seen them work like that when the gears have some wear, but not when they're new.


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## tjcruiser (Jan 10, 2010)

servoguy said:


> I don't know of any reason a worm drive should work better in one direction than the other.


Theoretically, I agree...

By definition, a worm gear transfers its power to the drive gear through a tangential force geometry. The force-moment-arm (and resulting torque) should be the same regardless of whether its a forward or reverse motion.

Now, in practice, I also agree that gears can get worn in odd ways, inducing more friction in one direction than the other.

The old adage ...

In theory, there's no differece between "in theory" and "in practice"; but in practice, there is!

TJ


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## gunrunnerjohn (Nov 10, 2010)

I've had several examples of "in practice", where they'd run better in one direction.


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## servoguy (Jul 10, 2010)

TJ, the real trick is to make theory and practice converge. This is usually very difficult and occurs very seldom.


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## eljefe (Jun 11, 2011)

I have several 1950s vintage diesel locomotives and found that most of them go faster backwards than forwards.


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## servoguy (Jul 10, 2010)

What are the numbers on your locos? I have a 2023 that runs real well backwards or forwards. I have a 42 Picatinny Arsenal 2-4-2 switcher that definitely runs better in one direction. I have a GE 44 ton that I seem to remember runs better in one direction. I think all the other ones are OK and run about the same in either direction.


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## eljefe (Jun 11, 2011)

All of these run well either way but it just seems they go a bit faster backwards than forwards: a 220, two 2343s, and a 2353. I think it's one of the 2343s that has a tendency to trip the e-unit when going forward but always runs smoothly in reverse. I have a 2023 on the way, so we'll see how it compares.


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## Big Ed (Jun 16, 2009)

Most of what I have run like a bat from hell forward or backwards.

I guess the brushes have nothing to do with how the engine runs in reverse?

I always thought if the train is run forward only and rarely went in reverse (as many run their O), that the brushes get worn so that when you use reverse it won't run as well.


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## servoguy (Jul 10, 2010)

I have a 2333, 2343, & 2353. If they don't run the same in each direction, I never noticed.


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## T-Man (May 16, 2008)

I checked my Burlington and I am also missing the ground spring.hwell:


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## dbyll (Oct 22, 2011)

I have the ground spring on order and will let everyone know if the does change the speed in reverse. Thanks again for all the help.


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## T-Man (May 16, 2008)

I doubt if it will. A bad ground would not be prejudice to direction.
The quirks of a worm drive offers the best explanation so far. I don't have much experience in operating the diesels. Mine operates slow but steady. With my steam engines I can clearly see some run better than others. A plus for having a fleet at your disposal.

I have one last question. Which way is forward????? Cab or Nose?


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## plandis (Oct 5, 2011)

*worms and rings! a second look?*

back to the question on practice vr theory-- good post by the way. The reason you will see and many have experienced the better running in one direction over the other? the worm and ring connection is very friction sensitive. With the inclined plane (worm) sliding across the teeth on the ring, the contact surface is doing a a lot of sliding friction and the load is transfer or held as thrust on the worm shaft- not so much axial load like helical gears place on the shaft. when this happens, the thrust washer (bearing) must be as friction free as possible. now- imagine a vertical mounted rotor(motor) with a worm gear cut into the output shaft. The worm on the end of the motor shaft is always trying to "screw itself into or screw itself out of" the ring gear. guess what? even with all new bearings/washers/brushes the motor still seems to run better in one direction anyway - not a theoretically condition but a real world practice. this is because the motor rotor thrust bearing has a helper in one direction - GRAVITY ! it actually places a lower thrust running on one direction on the thrust washer (bearing). If this theory is correct, then you would see negligible difference if the motor rotor where running horizontal. I wonder how that hypothesis could be proven?

thats why you experience a slightly better running n one direction vr.the other.


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## gunrunnerjohn (Nov 10, 2010)

I'm guessing wear and friction would have more effect that gravity. I'd test that theory if I could get the magnatraction to hold the train on the tracks at a 90 degree angle!


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## Big Ed (Jun 16, 2009)

big ed said:


> Most of what I have run like a bat from hell forward or backwards.
> 
> I guess the brushes have nothing to do with how the engine runs in reverse?
> 
> I always thought if the train is run forward only and rarely went in reverse (as many run their O), that the brushes get worn so that when you use reverse it won't run as well.



No one answered my question.

What does all think?
*Brushes would have nothing to do with it?*

Say you run the train for a 100 years only forward, then decide to use the reverse, the brushes being worn in running forward for 100 years wouldn't affect the engine running in reverse?


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## gunrunnerjohn (Nov 10, 2010)

I've seen the brushes have an effect, but for the most part, I'm betting on the gear train wear.


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## servoguy (Jul 10, 2010)

2333, 2343, 2353 are F3s. The forward direction is pretty clear.


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## dbyll (Oct 22, 2011)

thanks, foward to me is where the operator would be sitting, in the real world.


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## gunrunnerjohn (Nov 10, 2010)

dbyll said:


> thanks, foward to me is where the operator would be sitting, in the real world.


Depends on the specific locomotive, think steamers where they all sit in back.  Well, except for the cab-forward, or the camelback where they sit in the middle.

There are diesels that run with the engineer in the back, GP-9 for instance.


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## servoguy (Jul 10, 2010)

One of the most interesting steam engines is a Beyer Garratt. The engine can run either direction, so turn tables are not necessary. The engineer sits in a conventional looking cab at one end of the boiler. Garratts are articulated locomotives with an engine at each end and the boiler slung between the two engines. So, a Garratt doesn't really have a "front" or "rear."


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## Dave Sams (Nov 24, 2010)

servoguy said:


> What are the numbers on your locos? I have a 2023 that runs real well backwards or forwards. I have a 42 Picatinny Arsenal 2-4-2 switcher that definitely runs better in one direction. I have a GE 44 ton that I seem to remember runs better in one direction. I think all the other ones are OK and run about the same in either direction.


I bought a GE 44 ton switcher over the weekend. It looks like the motor shaft rests on a ball bearing, while the top end uses a "thrust collar" as the bearing surface between the brush plate and the armature. This could explain why it runs better forward rather than backwards.

The #50 gang car has ball bearings top and bottom. Both of mine run equally well in both directions.

Since vintage steamers have horizontal motors and don't use any thrust bearings, they would run equally well in both directons. In theory.


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## servoguy (Jul 10, 2010)

Not all of the steamers have horizontal motors. The 726/736/671 have worm drives. The other Pennsylvania steam turbines also have worm drives.


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## Dave Sams (Nov 24, 2010)

How do they run? What kind of thrust bearings do they have?

All my steamers (both of them ) have horizontal motors.


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## servoguy (Jul 10, 2010)

The worm drive steam locos run well. As far as I know, they all have ball bearing thrust bearings in the motors and very low friction.


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## Dave Sams (Nov 24, 2010)

Thinking about my inventory a little more.

My Burro and Trolley, and at least one other loco, have a set screw as the top thrust bearing. If there is too much play the motors are quite noisy. But they seem to run equally well in both directions.


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