Lionel 736 Berkshire

Dieseler,

Why may I ask? Since the motor in the 736 is such a workhorse. It's hard to improve something that's been around sixty plus years. To this day many of the early postwar locomotives are still around and going around many loops of track. This is all IMHO

They're functionally identical.

You absolutely correct .

Reason i ask is i have several 736 well used and several 681 engines.

The 681s do not have a lot of mileage on them.

Have gotten back into running these more on the layout nowadays.

One of the 736s i run makes a noise even after cleaning motor and cleaning worm wheel in frame and re greasing.

Checked Worm wheel and its in excellent shape so i unsoldered the motor out of 

1 of our nice 681s and installed in the 736.

Ran it off and on for a good week and it runs very quiet and smooth.

I checked the armature shaft end of the 736 motor and found it to have

wear on 2 of the spirals of the 5 or 6 spirals on it several of those are thinner than the others.

Out of curiosity i put that same worn motor in the 681 and ran it very very briefly

and found it to be the wear on the armature shaft grooves causing the noise.

Thought well the worm wheel in the 736 should have wear since its brass and the softer of the 2 metals in contact not steel like the armature shaft and figured since this engine was bought used somewhere along the line someone may have switched out the motors.

Have ordered several new old stock 681-114 armatures for the engines i have and  have spare worm wheels to keep them running well and curious as the 8002-100 looks like the 681-100 old postwar motors except for the spacer under the windings which the new ones use a c-clip in grove of shaft

to keep the windings gap space on the underside from rubbing on the spot that goes into the motor frames bearing area.

Guess i like to have lots of spare parts on hand even recently received pair

of spare motors for our MTH diesel as those motors seem impossible

to get into once the tiny brushes wear out but will open them up one day

once they start acting up.

<input id="mac_address" type="hidden" value="" />

Can motors weren't designed to be repaired.  If one wears out, even if you get it open you can't really do anything to repair them.  They're designed to be tossed and replaced.

Agreed. The postwar versions of the universal motor (before ~1960) were built as well as they could possibly be built. I believe that postwar motors were actually manufactured in Italy.  The tolerances were tight and high quality (for the time) laminated wire used.  

The issue is that everything becomes obsolete over time and Lionel refused to update the motor in any way. In fact, Lionel only cheapened the motor. I have replace bearings in many of my universal motor locomotives. In doing so, I found that the drive shafts in the postwar locos were always the same dimensions; very precise.  On the modern locos the armature shafts range from 0.1835 to 0.1865. In other words, lots of slop.  The red and green laminated wire, while colorful, is as cheap of laminated wire as you can get. The rotor of the Pullmor motor is very large and could easily be made into a 9-pole or even 11-pole armature; yet Lionel refused to do such a simple modification and doggedly stuck with a 3-pole design. Anyways, I could rant on and on. 

One thing that I have done to many of my universal "Pullmor" motors is add ball bearings. Ball bearing make a world of difference. Since this is a berkshire thread, here is my Santa Fe berk (actually Mikado, but same tooling) from the early 1990's and has the trusty 681 motor. 

Here is the ball bearing next to the worm

And here is the main motor ball bearing which is quite a bit larger.

And here is the motor assembled with its ball bearing in place. Depending upon the particular motor, there needs to be some modification of the armature shafts due to the amount of slop in the dimensions of modern construction.  

Does the motor achieve can motor + speed control slowness. No. It is still limited by its 3-pole design and 8:1 gear ratio. It does operate much slower than it did before, tho. I would challenge anyone to tell the difference between a can motor and this motor during operation. It is a quiet as anything. 

I believe that Robert Grubba said that the Lionel Pullmor motor reached the pinnacle of its mechanical evolution. A simple modification as shown above illustrates what nonsense such a statement was. Of course, the shenanigans of that man sent Lionel into bankruptcy.  

BTW here is a flat faced commutator and armature from a universal motor used for a pump. Looks just like Lionel's armature so there was absolutely no reason that Lionel could not add additional poles to the Pullmor motor. 

During the 1950's, I don't think there was a demand for engines to do what they are now:  prototype slow speeds.  Most Lionel ops more than likely ran fast, like Gomez Addams.

With Lionel's downward spin to General Mills,  they only thing L wanted to do was to cheapen items, not make them better.  A 5 or more pole motor would have helped at lower speeds, and prevent clogging.