# Conrail SD60 Doesn't move



## ConrailFan (Feb 22, 2014)

Hey all, I have a Conrail SD-60 recently acquired with knowledge that it doesn't move back or fourth. Railsounds 2 works fine, but pullmor motors hardly turn. When the throttle is all the way up, the green light flashes. I replaced the e-unit but it is still inoperative. Funny thing when the truck is bench tested with clip leads, the motors run fine. Engine cab# 5500, Lionel number 6-18216. Any ideas?


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## gunrunnerjohn (Nov 10, 2010)

First step is to pull both motors and clean out the grease in the trucks and repack with quality grease. Also, then the motors are removed, the wheels should turn freely. You'll want to lube the axles and gears with some 30W motor oil. If these motors have the adjustment screw on the top for the axle play, the correct setting is to go where you just remove all the play, then back off about 1/2 a turn. The motor axle should be able to move about 1/32" up and down when you try to move the wheels back and forth.


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## ConrailFan (Feb 22, 2014)

*Still no go!*

Thanks for the advice. I cleaned and lubed each truck, cleaned the commutator, and adjusted the end play screw for the motor shaft. I checked the wiring against the diagram I downloaded from Lionel and everything checks out. Whilst the trucks were off the engine, I 'jumpered' each of them and tested them on a short piece of track, they both separately worked excellent. The coil resistance on both windings are 1.2 ohm and the armature for both are 1.3 - 1.4 ohm. I reassembled everything and checked the wiring again for any bad connections, put the engine on the same short piece of track, and no go. The motors turn very little and if I increase power, the green light flashes. I am at a total loss why this engine doesn't go. The Railsounds 2 work fine though. I replaced the e-unit board before I did all the testing. The only thing I noticed is that the wiring schematic shows a coil on number 2 truck but not on number 1 between center post(green wire) and ground. I'm assuming that is the coil on the field. Also the second truck(or trailing) brush cap is stamped number 1 instead of number 2 like the wiring diagram shows. These are the only things that are different. I can't understand this! Any help appreciated. Thanks


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## gunrunnerjohn (Nov 10, 2010)

I think I may have the answer.  Suspend the engine and jumper power to the frame and roller. Check the rotation of the wheels, my guess is they're going in opposite directions. Reverse the brush connections on one motor if that's the case.


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## ConrailFan (Feb 22, 2014)

*Still no go*

Ah, great idea. Bench tested and still does not move. I jumpered as said and the motors turn very slowly, if at all and when more voltage is applied I get the green flashing light on the transformer. I unplugged the connector between the two trucks and the front truck works great, fwd, neut, rev. but as soon as I plugged the rear truck in, the front one just stops. As the motors turn very little, the wheels are both moving in the same direction, so the wiring is correct. It almost seems like its taking way to much current to run both motors. Could there be a defect in one of the filed/armatures that are not seeing? Could lionel have the wrong e-unit board for this engine? Also, on the board, there are 'jumpers' in the block closest to the r/h side. Does anyone know what these jumpers are for? Could the jumpers be in the wrong position? This is really a mystery, again, both trucks were tested individually and worked great, put them together(wired) and no go. I'm soon ready to just replace the field and armatures, but there's no guarantee that will solve the 'no go' mystery.


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## gunrunnerjohn (Nov 10, 2010)

If they're running properly, can you measure the current each one is taking by itself? If you have a shorted turn in the armature or field, the motor will draw excessive current.

Any idea when this was made? I'd like to look up the wiring diagram. I found this attached diagram for a Conrail SD-60, is this what you're using?


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## ConrailFan (Feb 22, 2014)

*No go SD60M*

Yes, that is the same diagram I'm using. I have come to that conclusion as well that one of the motors is drawing too many amps. What is the unladen(no cars or load on the motor) norm amps? Strange that both coils are reading 1.2 ohms. I will try measuring the current with a different ohm meter, I can only measure up to 10A. FYI, I'm using a CW-80 transformer, and the engine was made in 1994. I will reply with the results. Thanks again.


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## gunrunnerjohn (Nov 10, 2010)

That locomotive will probably draw 3-4 amps starting up at most. I'd first make sure that everything is turning freely, then measure the current draw for each motor individually.


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## ConrailFan (Feb 22, 2014)

*SD60 still no go*

Upon startup the ampmeter I am using immediately exceeded the 10A limit and blew the fuse. I'm not sure which motor is actually bad as I tested both on the track. I have to get more fuses. Will keep updated.


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## gunrunnerjohn (Nov 10, 2010)

Something is clearly wired wrong if it's pegging at 10 amps! That will smoke the reverse unit in short order, so I'd start testing the motors independently without any electronics in the picture or you'll be buying another one.


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## ConrailFan (Feb 22, 2014)

*Conrail SD60 Doesn't move test results*

OK, here are the test results(please note the last post about blowing the 10A fuse on startup was my fault....the meter was still on DC amps instead of AC. I have since corrected the problem.) Both motors were tested seperatly with no e-unit hooked up and throttle at full speed. Front truck: FWD 1.3 amp, REV.84 amp(and running very oddly varying speed) Rear truck: FWD 1.3 amp, REV 1.2 amp. First conclusion was someting is wrong with the front truck only drawing .8 amp and running rough and varying in speed only in reverse. More tests followed: Front truck resistance check from center lug to left motor brush was 11.3 ohm, center lug to right brush was 14 ohm. Check rear truck same way yeilded no resistance to motor brushes from center lug. Is that normal? More tests followed: Full speed on front truck going FWD voltage at blue wire lug 16.4 vac, yellow wire lug 8.2 vac. In REV (the suspected problem) blue wire lug barely 5 vac, yellow wire lug 16.3 vac. The rear truck was also checked voltage in both directions yeilded about 8 vac and 16 vac for both lugs and viceversa in an opposite direction. So my final conclusion would be there is some type of abnormality in the front motor truck. What could it be? A defective armature or a defective field? Please note that the engine was also checked with everything hooked up normally according to the wiring schematic supplied by Lionel, and only drew barley 2 amps and the green light was flashing on the transformer and the engine did not move.


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## gunrunnerjohn (Nov 10, 2010)

Are there 1uf caps from each brush to the motor frame on both motors? If not, you might install those, they're 50V non-polarized caps.

What is the "center lug" you're referring to, the field winding? I'm getting lost in the foot work.


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## ConrailFan (Feb 22, 2014)

*SD60 still no go*

There are no capacitors on the motors at all. Yes the center lug is the one going to the field winding, normally where the green wire is soldered onto. What will the capacitors do other than filter out unwanted spikes? Like I mentioned before, the front truck runs great in fwd, but rev it struggles to reach full speed, if at all. It's very strange indeed being there is a resistance measurement between the center lug(field wire) and each motor brush where the rear truck doesn't. This has got to be one for the history books.


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## gunrunnerjohn (Nov 10, 2010)

I'd break it down and measure each part individually, I think it's time for some logical debugging.

Disconnect the field on each motor from anything and measure the resistance of the field coils on each motor. 

Remove the brush plate and measure the resistance between each adjacent commutator segment. They should all match withing a few percent. Work your way around the commutator until you've taken three measurements which will have tested all three segments.

Make sure the brushes are good, the commutator is clean, and the gaps between commutator segments are not filled with crud.

If all that looks good, my next step would be to wire the motors directly to track power and run it through it's paces. If that works, swap the brush connections for each motor and run it in the other direction.

You need to start eliminating possibilities to get to what is actually happening.


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## ConrailFan (Feb 22, 2014)

*SD60 still no go*

OK, more test results as follows: Both trucks dissasembled, commutators cleaned, and de-soldered from all lugs. The front field coil now measures 1.0 ohm, the rear 1.3 ohm. The front armature all three segments read 1.2 ohm, the rear measured 1.4 ohm between all three segments. I track tested the rear truck with normal results, both fwd and rev works perfectly. The front truck works fine in fwd, but rev is slow and erratic speed. I also bench tested the amp draw again, and the rear motor draws 1.3 amp in both directions. The front motor draws 1.2 amps in fwd but rev only draws .8 amps. I did notice the front truck would not start up occasionally unless I spun the armature, then it took off. I also can't 'feather' the front truck like I can the rear, in other words, the motor will not start to spin until I reach about half throttle. The rear motor starts to spin very slowly upon start up and responds to the throttle immediatley. My gut feeling is something is wrong with the front motor. Any other ideas?


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## gunrunnerjohn (Nov 10, 2010)

Well, if you have a shorted turn on the field or the armature, you'd likely see odd results from the motor.

What I'd do now is swap the armatures from the front motor to the rear and vice-verse and see if that moves the problem to the rear or it stays in the front. What we're trying to do now is narrow the field of suspects.


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## ConrailFan (Feb 22, 2014)

*SD60 no go now has broken worm wheel*

OK, during testing, one of the plastic worm wheels broke. Lionel part # 600-0623-022. Lionel says its discontinued, is there a replacement out there for it? I can't find that part number anywhere. Thanks.


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## gunrunnerjohn (Nov 10, 2010)

Probably not, my suggestion is to try the train parts vendors like The Train Tender and see if they have it.


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## DonR (Oct 18, 2012)

Would that part be a candidate for a 3D printer?

Don


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## ConrailFan (Feb 22, 2014)

*A new worm wheel*

OK, I got a new worm wheel, whats the best way to press it on to the mag. axle?


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## gunrunnerjohn (Nov 10, 2010)

It appears you have to pull the wheel and then press the gear on. I normally take these to Harry Henning, he has all the presses and expertise to do the job.


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