Postwar 736 - Lack of Power

If the wheels are spinning you got power but no traction.  736 is s'posed to have Magne-Traction, according to the Postwar Lionel Trains Library.  Maybe it got de-magnetized.

Pete

What sort of track are you using? Magnetraction does not work with all track systems.

How about the tender and cars,  are they properly lubricated?

Another possibility: something is lifting the drive wheels off the rails slightly. Are the pony and trailing trucks in their proper places?

Lar1844:  I would look at the brushes and the brush springs and make sure that they are not too short (brushes) or weak (springs). Clean the commutator on the armature and check the thrust of the armature in the motor housing - no more than .010ths play forward or back.  Use the 671 metal thrust washers to adjust any excessive play.  I usually try to align the armature pole laminations with the field laminations and place washers either at the top side of the casting or at the bottom of the casting as needed.

          Also check the angle of the motor in regards to the mesh of the sprial armature shaft to the axle gear. In days of old LIONEL, thin washers were used under the casting around the aligning pins to adjust the pitch/angle of the motor to the gear. Now a days, they have a small set screw in the bottom of the frame to assist in adjusting the motors pitch and gear mesh.

          As regards the wheel spin, as was noted, this loco should have magne-traction. An easy way to tell is to look for a silver cylinder under the loco frame between the rear drivers. If it is there, then perhaps as was mentioned, the magnet may be weak or lost it's charge. It can be re-charged if it is either.

          If the silver magnet is not there, then you may have one that was a 726RR that was made without the magnet during the Korean War and is more prone to slip the drivers under load, but then that is what the real ones did!

          I would also check the side drive rods for excessive wear in the holes were they are bolted to the wheels, ovaled holes can cause drive problems in one or both directions. 

          Last but not least. lubrication at the proper points always will help a locomotive run smoother.

Hope this helps,  Dennsi M.

Don't forget that you should pull the armatures out of these and clean and re-grease the ball bearings and reinstall them and the washers in the correct order along with lubing the bushings the armatures ride on. This makes a big difference in power and current draw.

Rob

There's so many things this could be - most already mentioned by the other posters. IMO 4 aluminum passenger cars, if postwar, is a very heavy load for this type of engine. Lionel's short movie Iron Ponies from 1951 shows one of these Berks flying by pulling these cars. I think something special was done to that engine. 

I have a plastic truck era 736 as well.  It ran like crap until I disassembled the motor completely.  Cleaned all the bearings and the inside of the armature shaft housing itself (q-tips) and re-lubed it.  Now it runs great.  Spinning wheels just means no traction, not really a loss of power, so the motor might not be your problem.

You might also make sure the four passenger cars have clean wheels and roll freely.. 

Even with magnatraction, the wheels will spin if more load is applied than the engine can handle.  Both engine and car condition are variables in that equation along with the track.  Set the engine on a loose, single,  piece of track.  Pick the engine up without touching the track.  If the track comes with, then the magnatraction is probably in decent shape. 

How does it fun without the cars?

This may also be a clue that your track needs a little work to improve continuity such as feeder wires, good track joint's, etc.  Once you really load the engine down the available power to the engine just may not be enough to pull the load.  Remember the old Pullmor motor's do draw some big time amps compared to most of the modern can motor engine's.

What ever the problem is, you can fix it, and you won't need to send it to Lionel or MTH!!!  Classic Lionel RULES!!!

Thanks everyone.  I just replaced the brushes.  The results are better HOWEVER....unit still hesitates in forward gear.  Runs wild in reverse!!!  Also, noticed a "wobble" and the engine runs forward.  The wobble has me concerned.  Again, I am thinking gears.  Took motor apart and cleaned thoroughly as all of you described above.  Looked at motor and how it meshed with drive gear and it looks good.   HOWEVER, the drive gear moves to left and right a bit before I put motor into it.  All connections are good.....with the new brushes it runs better..but can't explain for the forward hesitation.  Still didn't try to pull any load......figured I would get it running smooth first.  Magne-traction is STRONG....so that issue is non-existent as part of the problem.  Any other suggestions to look at would be appreciated.....Thanks to all of you again.....You all are the best!!!!

Larry Williams

Lar1944:  As regards to side to side movement of the gear/axle assembly.  Check the gauge of the rear driver set.

          Besure that the wheels are parallel to each other and perpendicular to the axle. 

          Lastly  -  wait for it  -  axle bushings!!!!!

If all the above are okay, then you may have worn axle bushings on the crown/shoulder that touch the rear of the driver wheels. These have been known to wear in excess if a loco is run in a particular direction  over a set course for long periods of time.  They can also crack and chip and otherwise fall apart with age and stress. 

          Worn, they allow the wheels to rub against the frame of the loco, and with magne-traction, the magnetic force  (the FORCE)  will act as a brake against the wheels causing difficulty moving.  Check it out.  Dennis M.

The right rear axle bushing is always the one that wears out first(from forward operation), pushing the axle left, the right rear wheel into the frame, and the worm wheel off center.

Use one(or two or as needed) 671M-22 clips/retaining rings and snap them on to the drive axle to the left of the worm wheel.  You want to have between half to the full width of a 671M-22 clip of end play in the axle for best performance. Keep the entire gearbox & axle lubed well with a synthetic HP grease(Lucas Red 'N' Tacky #2, eg.).

If you can source some clips with the same inner diameter as the 671M-22, but larger outer diameter, that would be beneficial.  The last good tip I heard was to use an appropriate number of plastic bread closure clips(cut to be round) instead of the 671M-22.  Very little friction with that method and they too slip right over the axle and stay on.

Your solution seems very plausible!  I am in the process of checking it out.  Also I like ADCX Rob's solution just below yours.  Thanks again...

Larry

Most of today's track does not work well, or at all, with magnatraction.  The track must have steel rails and there needs to be regular steel bridges between the outside rails.  With tubular track this is the ties.  Super-O has steel stampings in several of the plastic ties.  If the rail is stainless steel, it may be only slightly magnetic.  Brass is not magnetic at all.  For best results, a magnet needs a complete loop circuit.  Think of a horse shoe magnet with a keeper on it.  I do not think any of the new track or any of the wood tie track has the steel bridges in it.

FasTrack has steel plates connecting the outer rails. In my experience, Magne-Traction works very well with this. My old 2046 can lift a piece of FasTrack into the air. 

True.

Not true.  Magnetraction works on GarGraves.  GarGraves just doesn't have as much rail mass as regular tubular track.

Those plates are for electrical continuity, not for Magnetraction.  Magnetraction works just as well(no noticeable difference) with the plates removed from Fastrack.  The amount of steel is far more important than the presence of crossties under the track.

ADCX Rob:  "Thanks" for adding some more light on the subject of the magne-traction and the rail.  However, I will differ with you as to whether or not the magne-traction is not enhanced with the use of the metal (steel) track ties. 

          Case in point:  I was  setting up some track on a wall display and was using the very early K-Line 36" lengths of tubular track on which to mount the train engines and cars.  I noticed a very strong  "attraction" of the wheels on this type of long track ( looks like Lionel  O72 curves with all the extra tie plates).  So I got out a  Lionel 2383 type four (4) wheel power truck, less motor, and placed it on a section of the long and very "tied" straight K-line track.   As I rolled it along under hand power, I felt the grip of the Magne-traction  was much stronger as the wheels passed over the tie plates than when it was between them.  So yes, as you said, the tie plates are not needed for the magne-traction effect to work; however, it is more enhanced if they are there, and if there are more of them, then, it seems to be even more effective.

          You and I have all done the  - put the loco on a piece of track and see if it can hold on to it -  to do a fast test of a loco's magne-traction -  Now try the rolling of a magne-traction truck over a reguler piece of straight track (steel of course) and then a piece or two of  O72 straight or curve track with the extra tie plates, and note/feel the difference.  I recommend tubular track, as this is what I used and we want to test "apples to apples".  Let me know what you find.  Dennis M.

Enhanced, yes, but not because the ties are "completing a circuit".  There's just more steel under the wheels.  You wouldn't get the same effect from Fastrack where the flimsy little electrical crossties are installed beneath the roadbed.

ADCX Rob:  I think many of us have been "schooled" by the early examples of how Lionel made magne-traction work in their trains. The front of the train set-up manuals would show several examples of how the magne-traction effect works.

          To quickly sum it up: One showed an axle made of magnetic material; another showed an axle with a magnetic core and iron pole pieces that the wheels were pressed on; and another showed the magnet placed above and between the wheels and stainless axles were used to not short the magnetic flux from passing thru the wheels to the rails and finally  "THRU THE TRACK TIES" to return to the opposite side of the magnet.  The metal track ties  facilitate the path for the magnetic flux to follow and  produces the adheasion to the track for traction.

          We are average folk and the  most science some of us have had was watching "Mr Wizard" on Saturday mornings. These examples that Lionel provided made it easier for us to understand this concept.  "Thanks"  Dennis M.

Dennis,

I THINK I found the problem based upon what you suggested above.  I took the motor out again and looked at the worm gear.  In one of my posts I said the worm gear moves "easily" to the left and right.  Well, when it moves to the right approximately 1/16" the wheels (all eight) seem to bind.  When I move it to the left, the wheels move freely.  I don't know if that would solve the pulling power but it appears a shim or something would solve the problem of moving the gear to the right.  Someone suggested the plastic clip used on sealing bread bags...cutting it into a circle and wedging it between the gear and the side of the frame.  Does this sound feasible to you???  Thanks in advance..

Larry

Lar1949:  I think ADCX Rob noted the use of the plastic shims.  I have not used that type of item, so I can not supply any data as to it's longivity as a repair. It may very well do the job and at a small price too.  I would venture that if you prepared the shims properly, they are worthy a try.

          I do it the old fashion way and pull the wheels and replace the axle bushing, if it is worn,  or add the 671M thrust washers to the outside of the axle behind the wheel before I press it back on.  This of course is a major operation as you must remove two wheels, the blind one first so you can remove the geared axle wheel due to the wheel flange being behind the wheel it is next to.

          Some attempt to cut a pie segment out of the 671 thrust washer so it looks like the letter  C  and then insert/snap it over the axle, behind the wheel next to the axle bearing that is offending. This can be done, but it is a pain in the neck(?). 

          Try the easier approach first, and if it does not work then try the next one.

Dennis M.

Hey Rob...

Just wanted to send out a BIG THANK YOU for your suggestion about the "bread clip"!!!

IT WORKED!!!!  I trimmed the piece to fit the opening between the worm gear and the right side.  I pushed in down on the axle as far as I could.  I noticed it would move up a bit so I pushed alittle further with a flat tip screw driver and it appeared to "snap in" around the axle.  I put the 736 on the track and it pulled four postwar operating milk cars, a postwar ice car and a caboose....without as much as a slip of the wheels.  Put the cab back on and tested again with the same load and it crawls with 8 to 10 volts and speeds up well when given more voltage.  I don't know how long that shim will hold but I informed my friend who the engine belongs to....that the ole Berk is good for a few more miles before it will need further service.  

Thanks to all who responded......This forum is fantastic and so are the members!!!!

Best wishes..

Larry Williams

TCA 75-8293

Glad you are back in business.

Grease it all with a good HP synthetic and it will last quite a while.