1. Move the armature commutator closer to the brush holders. Place a .020 - .030” stainless washer in the motor bottom bearing support. Adjust motor end play to .020. This will provide a more reliable bearing for the armature and keep the commutator closer to the brushes.
2. Eliminate most resistance from the motor brushes. Add a pair of 1/16” X ¾” copper braids to the existing brushes. Solder each braid to the spring retainer on the brush holder top. Lift the brush spring. Install the braid to cover the top of the existing brush and form a ¼” loop above the brush holder. Notch a pair of worn brushes on one end with a jewelers saw .030 deep. Install the notched brush on top of the copper braid and place the spring end into the notch. Insure that the braid is located in the spring slot in the brush holder. Move the armature up and down to ensure the brushes move freely in the holders.
3. Eliminate most current from the E-units tiny contacts. Add a 10 amp miniature relay to the motor circuit. Install a 10 amp DPDT, 12 volt, ¾” squared relay onto the rear lamp post using double sticky tape. Install relay leads up. Wire one relay coil lead to the two E-unit reverse leads that show ground during reverse. Wire the other relay coil lead to a 1004 diode (plus side) and a 35 MFD, 25 volt capacitor. Wire the negative 35MFD cap lead to the frame. Wire the other diode end to the AC supply. Wire the relay common leads to the commutator brush holders. Wire the two sets of NO and NC relay contacts cross-wired. Wire the two cross-wired contacts to the AC supply. You have now created a 10 amp reversing circuit that takes all the current away from the tiny E-unit contacts and switches the main current through the 10 amp relay.
4. Reduce contact resistance to the track pickup rollers. Solder a 1.5”, 24 gauge, Teflon insulated wire to each track roller frame bottom edge. Use minimal solder for good connection. Solder each wire to the copper roller spring running the wire along the motor frame. Ensure the roller frame solder does not interfere with the track roller frame movement.
5. Install shims to the wheel axle bearing opposite the geared wheels. This brings the drive gears into better alignment and allows the gear train to run smoother. Use 1/8th” round ‘E’ clips to do this without removing the wheels. Place the “rounded” side of the E-clip towards the bronze bearing to provide better wearing conditions.
hook 1 wire to ground and touch the other wire to the side terminal on the e-unit where the hot leads are soldered. that's the lug on the fiber board.if the e-unit & the motor fires up then you have a bad wire or bad solder joint on the lead to the collector. if it does not run, then put 1 lead to the e-unit frame and then touch the lug with the other wire to see if the e-unit cycles. could also be a bad ground on the e-unit frame but it is hard to figure a problem out LD. all i can do is tell you how i check no run/no working e-unit problems.
hope this makes sense
Since we're on the subject of MPC Diesels, I was enlightend with my success over the advice you guys gave me, on cleaning the motor up on my CN Geep.
I then decided to give my (1975) Santa Fe GP-20 the same treatment, but the results were very different.
When I apply track power, the headlights burn, but no juice seems to be getting to the e-unit or the motor. Kinda like its locked out in neutral.
Moving the e-unit lever with the power on, does nothing.
I checked all the connections and they are good, no disconnected wires.
Any ideas?
If an engine with a Pullmore motor goes better in reverse, the plastic under the bottom of the shaft
might be worn, and a shim needed glued in. Which might cause the teeth to be worn and the
shaft/armature needs to be replaced too.
lionel used the low temp solder because of the cheap white plastic communtators used. that is why a lot of early MPC motors need armatures if they were run a lot. the late 80's showed the return back to the bakelite ones like the postwar armatures had. as the plastic melted the communtators the would sag and tilt. also have seen them spin on the shaft and throwing timing of the windings causing more current draw. a MPC diesel ,with 3 MPC cars should draw no more then 2 to 2.5 amps while running around the standard set circle or oval with the motor properly serviced and lubed. hope this helps.
No one has yet mentioned a problem with the MPC locomotives that can cause a variety of running problems from no motor movement at all to poor operation perhaps in only one direction. Sometimes this problem can cause a locomotive to run fine when cool but badly or not at all once warm. The solder joints on the armature in MPC locomotives were sometimes made with low temperature solder, which when operating hot could actually soften and be thrown off the armature. You might find silver patches within the motor, or even outside it. Any time you see this, it's worth your time to touch a soldering iron and a little high quality solder to each of the three solder joints at the commutator plates.
Thrown solder is a common problem with large electric motors powering irrigation systems and farm machinery in hot weather. I have never encountered it on postwar or prewar locomotives, only on modern era trains, and particularly on locos from the late 1970's through the 1980's.
Wow the info I have been reading here has me wondering I have a set of GP-9 dummy and power unit and they are new in box never been run there PRR 8357/8358 from 1973 - 1975. Looks like I need to check them out and see if they will run correctly. May need to open up power unit and check and clean everything first then put them on the track and test them out.
Life's hard, even harder if your stupid John Wayne
http://rtssite.shutterfly.com/
I have used a ScotchBrite pad to clean commutators. Works great. Also, any engine that has been sitting for many years probably has had the grease turn to cement or glue. I would recommend disassembling the motor and cleaning things up and then lubing with 5W-20 which will last 40 years without a problem. I just lubed a 2023 that I have had for 35 years, and it runs so much better.
BB
You're welcome! Sounds like you have a great fleet of Lionel units that will provide many more years of fun on your layout. I hope you can post some photos when the locomotives are running.
Thank You, Mark!
This is some great information! I have fleet of MPC Geeps, U36Bs and diesel switchers that need to be woken from their decades long slumber. Since I haven't run these, much less seen them in years, they will be like new trains to play with all over again.
I discovered that waking up the old CN GP7.
Once I really know what to do to get these old Pullmor motors going, I'm going to break out my "Spririt of '76, U36B set (with the 13 original state cars and caboose).
Thanks again for the help!
Tower49,
Take a look at my earlier post in this thread (4th one, I believe). I cleaned up my CN 8031 with the instructions from this link at Just Trains:
http://www.justtrains.com/Service/maint-main.asp
Print the pages from the Lionel maintenance section and just follow the instructions. There are detailed drawings and color photographs (before and after) so you can see how the parts (especially the commutator face) should look after cleaning. (You may have some carbon build-up on the commutator face and brushes.) I purchased the suggested cleaning supplies at a local Home Depot for roughly $20, but I'm sure the supplies are available at Lowe's or Menards, too.
After removing the two screws and upper half of the motor (exposing the commutator face), check the armature alignment. The spacing around the outer edges of the armature should be fairly consistent for smooth motor operation.
I'm sorry, but I can't advise you on the use of denatured alcohol. I've only used mineral spirits. I would, however, advise against using sandpaper, even if wet, to clean the various parts. 800 or 1000 grit wet (with mineral spirits) Imperial paper is better because it doesn't break down (and leave residue) as quickly as sandpaper.
Glad to hear your MPC-era locomotives are back on the tracks. Good luck!
Hi Rob:
She 'll start in neutral, and shell back down fine, but she just sits and buzzes when she's in forward gear. When pushed, the motor wants to go, but somethings holding it back (armateur turns etc.)
Like all my MPC Lionel diesels I bought in the 70's, she hadn't been run in decades.
This thread inspried me to dig out my old CN 8031 Geep, I popped the carbody, checked all the wires and they were fine, then I lubed her.
She was put up a fuss when I first ran her, sluggish, used lots of juice (16v @ 3.3 A) on the Z4000. The brushes were sparking blue. she limbered up a little after letting her run the iron for about 25 minutes, but you can tell she still doesn't run the way she should.
She really put up an fuss when I hooked train to it (all light MPC era cars), she pulled it, but under protest, she needs more help.
I need to pop the motor apart and clean it, Can I use denatured alcahol to do it?, How do I know if the brushes are hung up and how do I clean?
I've got a fleet of MPC era diesels that are probabaly gonna need this.
Please help
Thanks!
Tower49I do have a Santa Fe GP 20 ( think she's a 1975) that will only run in reverse. Any suggestions?
Any suggestions?
Not enough info.
Does it go to neutral when the power is interrupted, and then reverse again after 4 interruptions? Or does it power up in reverse and always goes reverse no matter how many times the power is interrupted?
Rob
Very interesting post, I have one of these animals (CN GP7), bought it new back in 1971 with a dummy unit. I don't think its been out of the box in 30 years (!).
Now you guys have me curious, I gotta try it. I do have a Santa Fe GP 20 ( think she's a 1975) that will only run in reverse.
Thanks for all the tips.Have never had a Lionel motor apart.Will have to give it a go when I get a chance.Will try reading the links posted above before going at it.
Here's one with the original early MPC box.
It also has the PW and hollow roll pick-ups.
http://cgi.ebay.com/Lionel-8031-CN-GP-7-Diesel-Original-Box-/380245156710?pt=Model_RR_Trains&hash=item588860a366
Ken: Thank you for writing about where you purchased your 8031 with the flatcar stakes. I purchased my first one from Savoy Merchandise in NYC, it came with plastic stantions, and had both sets of pickups. That one was eventual sold, but I've purchased a couple of others since then. All of mine have the plastic stantions. The one currently on my layout has both pickups also, but I bought that one used, so the second pickup could have been added at any time.
I guess I will be looking for one with the metal (flatcar) ones.
cwburfle One more thought on those hollow roller pickups:To me, they signify early (1970-1972) production where diesels are concerned. I've been looking for these early diesels. I find that if the rollers are carefully cleaned, they work OK on 022 switches, so long as the switches themselves are clean too. I am curious about Ken's 8031, because his has 2411 flatcar stake handrail stations. That is a fairly common configuration on the 8030 IC geep, but not so common on the 8031. But it is a reported variation (earlier than the one with plastic stantions)I wonder whether he purchased it new in the early 1970's, or later.
One more thought on those hollow roller pickups:To me, they signify early (1970-1972) production where diesels are concerned. I've been looking for these early diesels. I find that if the rollers are carefully cleaned, they work OK on 022 switches, so long as the switches themselves are clean too.
I am curious about Ken's 8031, because his has 2411 flatcar stake handrail stations. That is a fairly common configuration on the 8030 IC geep, but not so common on the 8031. But it is a reported variation (earlier than the one with plastic stantions)I wonder whether he purchased it new in the early 1970's, or later.
I purchased that 8031 new at the Two Guys store in downtown Newark.
That Two Guys, plus the one in Kearny is where a good amount of my MPC inventory
came from.
I would say that about half of the 8031's that I see on ebay from time to time have the log car/flat car stakes.
Ken
Most of these engines have hollow roller pick ups, that are so light they sometimes stall on switches. MPC also installed PW style pick ups on the dummy truck on many of the units, IF this is the case connecting the wires from the motor to the PW pick ups will solve any stalling.
Most of these engines have hollow roller pick ups, that are so light they sometimes stall on switches.
MPC also installed PW style pick ups on the dummy truck on many of the units, IF this is the case
connecting the wires from the motor to the PW pick ups will solve any stalling.
Most of the 8031 locomotives I've seen came with both the hollow rollers on the motor truck and the postwar style pickups on the dummy truck. Lionel (MPC) realized the problems with the roller pickups and actually sent kits to the dealers for field modifications (I have a sample of the paperwork).
Odds are that if the pickup is installed, it's properly wired. The 8031 CN Geep has a three position e-unit. The wire from the extra pickup would be wired to the power terminal on the E-unit, not to the motor. Attaching the wire to the motor would create problems.
If the engine does not have the extra pickup, adding it would probably be worthwhile. Here is a tip: one of the MPC Geeps that I own was purchased for a song because one of the rollers was missing from the power truck, and the housing was damaged so another could not be installed (later MPC version of the 2037 style pickup). I just added a 2328 pickup to the dummy truck (same as used on 8031), and now the engine runs great with three pickups.
Is this the engine you have ??
If so follow the advise given, with another suggestion.
That said, this engine is a very reliable runner, and even has numbers in the number boards.
I have the same CN locomotive and have experienced similar problems/issues.
As others have suggested, carefully check the wiring. I found a broken solder joint in my unit and simply re-soldered it.
As long as the locomotive is disassembled, you might as well clean the various motor components. Here is a great website for step-by-step Lionel maintenance:
With a little work (about an hour), my unit runs very smoothly. Good luck with your GP7.
There could be several factors here - you have a "new" 40-year-old locomotive!
The 3 most common problems are:
1)the e-unit fingers and drum are tarnished and need to be cleaned
2)the brushes may be hung up in the brush tubes and need to be cleaned
3)the brushes and commutator are tarnished and need to be cleaned
OR, it could be a combination of these, and/or a broken wire. One wire missing/broken from the brushes or field will exhibit the same symptoms.
As long as you have it apart, lube the gears(grease), axles & shafts(oil).
A wire may have come loose. I've seen this on the wires going from the e-unit to the motor. I have even seen cases where the wire looked like it was attached, ,but no current was flowing due to corrosion of the wire tips. If this happens you can unsolder the end, trim the wire, and re-attach it.
The motor might need cleaning. I have also run into early MPC engines that develop a non-conductive "glaze" on the commutator plate. Cleaning the motor will solve this.
The e-unit might need cleaning. Same as the motor.
I have actually run into all threee of these issues, tthese comments are not conjecture. (Which is not to say there couldn't be something else wrong)
I have a Lionel Canadian National GP7 that I purchased new many years ago.The locomotive has had less than an hours running time.Recently I put the loco on the track for a run.The light comes on and the loco hums.The e unit moves from one position to another but the loco does not run.
Does anyone have an idea what my trouble could be?
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