Matt,

I would strongly recommend to put the diode back between the spring holder, you will see in the instruction manual under 6.7.4.1, it says: the Märklin 5 pole motor has 3
anti interference capacitors 2 of them have to be removed leading to the motor housing and motor.
also necessary are 2 chokes between motor and grey and orange wires.
If you are contemplating to use more than 2 Aux functions you can get the adapter board 51968 and this allows you to tap into 4 Aux functions or 6 functions with the latest adapter board 51969.

to improve the running characteristics you will notice the right hand brush (last picture) shaft is slightly lifted by adding a very tiny drop of superglue between the brush shaft and the motorshield (without the brushes inside) and hold the parts together for 2 or 3 seconds, this way the brush will sit at an 90° angle and you will find the motor will run more smoothly, quieter and your brushes will last longer.

to reduce heat and avoiding the light defusers from deforming led's would be the way to go, you've already got the light sockets all you need is a resistor (blue wires) and you shouldn't have any problems in this department any more.

regards.,

John

Hi John,
The motor shield was a mess. The brush holders were rotating around the spring posts as well as lifted above the shield. I glued the brush holders, but have already ordered a replacement.

About your bearings, what size (ID, OD and width) are you using? Are they flanged? How do you drill the shield and frame? Curious how you keep the bearings centered with the original location. Piloted drill bit?

Hi Paul,
I did a search and found this:

https://www.marklin-user...2-motors.aspx#post430093

See post #6 for details

I've got some bearings on Ebay and a metric drill bit set I found at Amazon on the way. I'd like to get a 4mm drill with a 1.5mm pilot, but all my searches have come up empty. I think I'll ask my machinist friend if he can help.

Sorry guys for not responding earlier.

Ball bearings: measurements: 4mm (diameter) x 1.5mm (bore) x 2mm (width)

sometimes the ball bearings fits nice and tight into the back of the motor block, if not again the tiniest drop of super glue has to be applied, I use a toothpick and smear the superglue around the outer side making sure there is no excess glue you than line up the ball bearing against a hard surface like the edge of an office or working table and pressing the ball bearing into the block, of course you have to remove the plastic insert first from the outside in and in such a way that the protruding cogwheel doesn't get bend or damaged, insert the armature about a minute later (from the outside and make sure it is in the right position (90° angle)by turning it.

Motorschield: all I'm using is different sizes of drills starting from a 2 mm upwards until I get to a size of 4mm. by inserting the drill bit into a Dremel drill and than rotating it by hand you will be in control of the position of the drill and its centre location using the drill from the outside and inside on several occasions or in alternative drilling attempts.
You may find there is a small amount of excess plastic material around the newly created hole take it off with a Stanley knife but don't damage the newly created hole.
you than can repeat the procedure by placing the ball bearing on top of the hole and see if you can press it in, if your attempts fail try to enlarge the hole with your 4 mm drill again by moving the drill bit forwards and backwards in a rotating fashion. the ball bearing should not fall into the hole and you can apply quite a bit of pressure to press the ball bearing into the hole but it has to be large enough in the first place (your own estimation) without deforming the brush plate. again make sure the armature sits in an 90° angle by placing the armature inside the motor shield and rotate the armature and see if it has the same on all sides, left,right, top, bottom, if not establish which side is slightly out and take the armature shaft on the other hand and move it upwards or downwards slightly and than again try if it is centrally located, if you do not make sure the armature is in an 90° angle by placing the motor shield over the armature shaft and securing it with 2 screws you will find eis no free movement available.

You also will find older molds and motor blocks are not as refined as newer ones, to give you an instance I just bought a motor block for a Hobby ICE train to add a second motor into my consist of 10 carriages and 2 motorized end units. done everything I've described as above and no movement at all. I thna played around with only fasting one screw either the bottom or the top one and to my astonishment but not a total surprise the motor mold or its flat surfaces where the magnet lies on were not at an 90° angle, I've tried different methods trying to correct the abnormality but found there was only one thing to do is to pack the back of the magnet with some thin cardboard and I've picked a hole with a small screwdriver to let the screw through. it works excellent now.
So all in all be aware of it, some abnormalities can occur but you have to do your alterations precise so any variation in the motor block (most of us are not aware off) can be pointed towards one fault.

when everything has been achieved successfully you than can start assembling the whole motor, first your permanent magnet, than your armature, make sure it sits within the teeth of cogwheel and than push the motor shield onto the armature shaft, secure the screws on the bottom and top having done all this the motor should turn freely.

before putting everything together you can pre-solder the chokes on each side, add a ground solder pad onto the top screw.

always check your motor-shield and make sure the brush shaft is 90° angle or lying against the motor-shield

John