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Has anyone tried to grease their Lionel century club GG1?  When trying to grease the motor and gears I found a ball bearing between the motor and the truck on one motor? 

The engine seems to be binding as it runs. It had been running fine last year. Now I can not seem to make it happy, Any help would be appreciated. Thanks, Dave

Last edited by EngineDave
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Okay, not sure you will like this answer.  The ball bearing you found was to change the angle of the motor gear to the axle gear so they meshed properly.  While I haven't had my CC GG1 apart, I will likely find the same ball bearing.  Pretty sure I had to send my first issue Santa Fe FT's back to Lionel for a grinding issue.  There was a repair note  indicating that ball bearings were inserted to correct the gear meshing problem.

So, if you removed the ball bearing, or changed the motor it was mounted on, that's likely your problem.

Hope this helps a little.



I have my Century Club GG1 open for maintenance. I did not see your e-mail in your profile, but if you need any help with this engine please reach out to me before I put this back together.

Mine runs great, but had to fix an electrical issue when someone ran into the GG1 at a high rate of speed. It knocked loose a connection and I figured since I had this apart I would do a major clean and lube.

In any case, I have ball bearings on both trucks, so maybe your missing a bearing. I have no binding what so ever.

BTW, the parts breakdown from Lionel does not show the bearing in question.


Thank you everyone for your advice. I have been involved with Lionel trains for 68 years and to me, using a single ball bearing as a spacer seems to be a poor design. However, I love this engine and when it's running good, it really runs great. So, I removed all moving parts again, reassembled the engine and so far so good. We shall see, right now I am very happy!

Hello everyone:

TrainDave, I want to make sure we are talking about the same bearing. The pictures below show a single bearing in each trucks "stud well" (that is my term).

I also found it odd that there was a bearing there, and in fact, it is not listed in the Lionel service/parts breakdown. However… if that is all it takes to make this engine run as well as it does than it really is not much of a concern to me. Honestly, this is by far the smoothest running, twin Pullmore engine I have ever seen/run. Not "can" motor smooth, but pretty close.

GG1 Overall

Above: overall shot of Century Club GG1. Here is the link to the Lionel Service Parts breakdown:

Century Club GG1 Parts Breakdown

Motor Stud

Above: Stud on bottom or motor (outlined in red) that will ride ON the bearing. 

Ball Bearing

Above: Well in truck to hold bearing and motor stud. Bearing still has the original Lionel grease which was starting to become a little stiff.

Motor seat

Above: Image of the alignment of the truck/motor/gear and stud.

I hope this answers the question about the bearing. I will wait a bit before I button this project up. Any additional images you would like to see please let me know.




Images (4)
  • GG1 Overall
  • Motor Stud
  • Ball Bearing
  • Motor seat

Thanks Charlie .  Here is the Century Club GG-1 motor.  Item number 2 is the thrust bearings on the output shaft of the motor.  If a motor is not taken apart with care, that bearing race may break up and he may be seeing that.  I wish I could be of help but that is all I have on bearings in the motor.

Motor number is 610-8503-100.  This was the good Lionel Pullmor.  It was used in other applications.


century club


Images (1)
  • century club
Last edited by Marty Fitzhenry

Marty, I'm guessing the original poster was asking about the ball bearing under the positing guide stud because he said he saw "a ball bearing between the motor and truck", that is the bearing I'm trying to show in the pictures, not the motor shaft bearing. If you look at image three of what I posted, there is a single ball bearing (in the red square) that needs to be there for correct motor mesh. 

Again I'm guessing he may have dropped or lost the bearing during his first attempt and when he reassembled the motor to the truck he found the gear mesh not correct.

If, on the other hand, he dropped one of the motor shaft bearings and one of the five very small bearings came loose, then that is another matter. 

Based on EngineDaves response above, I think he was missing the single bearing, as he said the gearing was fine before the teardown, but not so good after. The bearing I show, is NOT shown in the Lionel parts breakdown, but does affect gear mesh and was present on both motors.

I do agree that the motors in this engine are some, if not the smoothest Pullmores I have had the chance to operate. Not sure what or why the difference, but they are very smooth running.


Last edited by Charlie

Hey Lioneltrainparts:

Thankyou, that is what I was looking for. The parts list you linked to does show the steel ball in question. Where did you find this?  I ask because when I type in the part number all I get are the gg1 list I linked to above and also a motor breakdown for the gg1 and the nw2.

thanks again.



These single ball bearings are a "fix" (similar to the added dimple now added to the top plate of motor trucks for F-3 and Geeps 7&9) that has the effect of reducing the depth to which the "worm" on the Pullmor motor shaft meshes into the "worm wheel" pressed onto the shaft joining the driving wheels.

This change was associated with the change from a metal "worm wheel" to a plastic one.  A basic problem with plastic gears is that their plastic gear teeth are only about 1/10th (one-tenth) as strong as metal gear teeth.  (Yes, I know that some gear metals are weaker than others, and there are some very strong plastics, but 1/10 fits the situation in these engines well-- I recently looked very carefully at that.  It seems I have some experience in very strong glass-plastic composites; I was a research assistant running an investigative research program while I was a grad student in engineering.)

What happens is that the purveyors of plastic gears, like what we have here, like to sell them as replacements for metal gears.  But to do this, there is the problem of weakness to overcome.  All the more so, because a case that can be made that the metal gears were already overloaded (remember that the 1st Berkshires had two worms and two worm wheels to handle the motor torque, as did the original F3s for many years).  I could find no product which would be a satisfactory grease for the one worm/one worm wheel (all metal) which turned two axles in the Geeps, Trainmasters, and later F3s, all with the vertical Pullmor.  (The required number is around 600; 300 to not quite 400 was all I could find; Red & Tacky was only about 315, IIRC-- well, tacky is good, even essential.  Lionel postwar grease may have approached 400, but I have no data for it, and today I can't find any commercial source.  The numbers are for kinematic viscosity at 40 degrees centigrade.)

So the weakness of the plastic teeth is typically made a lesser factor by increasing the base width of the plastic teeth.  Since the worm itself was not  changed, this makes the two sets of teeth interfere with each other unless the spacing between them is increased.  This will at some point cause problems which must be investigated:  lack of continuity of gear action (one gear will cut into the tooth tops of the other); lack of true involute action (uniform motion is not transmitted, leading to higher stresses on weaker teeth and thus earlier broken teeth).

Some data:  Lionel gears in the mentioned diesels are for spur gears associated with the vertical motors are 40 dpi (diametrical pitch inches) with a 20-degree pressure angle.  At some time in the middle 1950's this angle changed from the 14-1/2 degree pressure angle which had been standard; I do not know exactly when Lionel changed over.  Plastic gears are typically made with a 25- or 30-degree pressure angle.  I doubt that in this situation the "fix" would accommodate more than an increase to 25-degree pressure angle in the plastic worm wheel.  (Spur gears with the two pressure angles run only with considerable drag, as I demonstrated to myself by using newer geared wheels driven by a train of older gears (the motor truck became very hot and seized after about 15 minutes of running.)  The 25-degree tooth has a strength increase of about 2/3, so it's about 1/6 the strength of a 20-degree metal gear (a 30-degree plastic tooth would be about 1/4).

There is no standard for worm gears, but small wormsets as here are often made with crossed helical gears, and that is the case here.  There are several ways to cut helical gears, sometimes using spur cutters, sometimes special cutters; the later worm shafts I believe were not cut but deformed into blank shafts of adjusted diameter by roller dies.  (As Earle Buckingham wrote, there are 100 ways to produce an involute tooth profile; I adapted some moving bridge designs to test enclosed gearsets proposed by Earle Gear Company in actual service (locks and main drives except sector gear)).  Plastic gears of course are not cut but injection-molded in a die-- the die is expensive but in sufficient number the gears are cheap.  In theory, a very accurate tooth profile could be produced-- this is true for spur gears, but no method for worm wheel gears is known, some degree of running in is always required.

The worm can be taken as a rack by taking a slice along the centerline (the full method for continuity of action requires several parallel sections. offset along the pitch of the worm, say at least 5, which is a real pain).  Then the teeth of this rack have straight sides.  The worm wheel teeth have curved sides (a lot of them are simplified to straight sides, particularly plastic gears in model rr work with 1-thread worms).  This can be awkward here with a 3-start worm and non-locking ratio ~8:1.

The tooth size on the metal gears is about the same as the 40 dpi spur teeth, but the thickness of the gear is greater to increase the contact line and the continuity of gear action (1.0 is a minimum).  The metal worm wheels, being of the softer metal, wore or flowed to a line contact from the initial point contact of crossed helical gears.  This does not happen with a plastic gear wheel although there may be some elastic deformation to a more limited extent.   The mineral filler in plastic can be abrasive (tiny fibrous rock crystals) and may wear the worm.  These wormsets are open, which is a difficult lubrication condition.

The helix angle is about 30-degrees.  I have found that making a drawing works best for this type of analysis.  Grid paper with 10 squares to the inch can be used to draw the teeth and their mesh to a scale of 10 times enlargement, or even 20 times, can be used.  Drawing the rack is easy, but the teeth of a wheel gear have to be done by drawing the unwinding of a string off the base circle.  This line must make a 25-degree angle (plastic wheel gear) with the line of centers when it crosses it.  The line of centers to a rack (worm gear center here) is at a right angle to its axis.  For addendum, try the usual 1.0 pitch; for dedendum, same plus clearance, try 1.2 pitch for small gears.  The wheel gear segment could be cut out of a copy and rolled along the clearance line.  Metal gears can be shown using 20-degree pressure angle.

I will explain the results when I have them, but I'm not likely to be very fast with this.  Those with a little time can try the procedure above.  I've meant to do it for several years now.

Does anyone know whether the heavy scale GG-1s, first edition of some years back, have metal or plastic worm wheels?  I'm not anxious to take one apart just to see.  How is factory lubrication in these-- present, or sometimes not present?  (Just repeating reports for other engines.)  Present GG-1?  TIA.

--Frank M

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