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I've had this engine for some time now.  The first purchased many years ago when I got married and moved into my first home.  It always growled and ran tough.  This is one of the engines that had an issue with motor bushings.  Does anyone have the parts list needed and the procedure to get this engine up to par.  I always liked it and would really like to get it running as smooth as possible.

Thanks in advance.

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The following is from a forum member that I saved. Hope this helps. I also saved the articles from OGR, but, don't have them on a computer file.

 I recently did this repair and learned a couple of things. Bear with me, it takes a little explaining:

Not long after I saw this thread, my sister's Rock Island 4-8-4 started acting up. It had always been noisy, but now it would sometimes stutter and refuse to move. Pushing it a short distance would help. I stuck my little finger into the space between the ends of the stationary field laminations and pushed on the armature. Bonk! Bonk! Sure enough, obvious play, and the source of the noise.

I tore the engine apart. The worm gear looked OK, so we just ordered new bearings, as shown in the repair article. And got the wrong ones. After some sleuthing, I realized that that the diagram in the article, which is the same as the diagram in the Greenberg's guide, is in error:

motor wrong

There are two problems here. The first is that the "Front Bearing," part number 2020M-17, is shown on the wrong end of the motor. It should go on the gear end, which is toward the front of the engine. Not too a big deal if you are ordering both bearings.

The bigger mistake is the "Rear Bearing," part number 671M-20. This does not fit the LTI Northern. If you try to install it into the Northern, you get this:

That's the 671M-20 bearing sticking out of the motor housing, with the ball bearing race ("Thrust Bearing," no. 681-121, in the diagram) between it and the armature. Below is a photo of the 671M-20 (left) next to the bearing which we eventually installed. A big difference!

I seemed to remember hearing that the horizontal motors made prior to 1950 did not have the ball bearings contained in a race: they were loose in the motor. In the picture below, you can see that the 671M-20 is counter-bored, I presume to trap the ball bearings against the armature shaft. So it seems that this rear bearing is correct for pre-1950 engines only.

As you can see in the photo, the correct rear bearing is part number 681-120. The clue to that was the number of the ball bearing race (a.k.a. "Thrust Bearing"): 681-121. When assigning numbers to new parts, Lionel tended to incorporate the catalogue number of the item in which the part was first used. So the race was new in 1950 with the 681 Turbine. Trying to put the 671M-20 bearing into the Northern made it obvious that it and the race were not designed to be installed together. When the 681-121 race debuted in 1950, a new rear bearing must have been designed to go with it; likely, it also had a number starting in 681. There is no diagram that I know of for LTI's Northerns, but they are clearly based on the chassis used by the 736 Berk and the 746 J.  But the Greenberg's repair manual shows the 671M-20 rear bearing, together with the 681-121 race, on those engines as well.

I finally found what I was looking for in the MPC parts lists. The 8002-100 motor is specified for the N&W J reissue; there is no diagram, but there, at no. 5 on the parts list, is the missing link, Rear Bearing, number 0681-120!

So we ordered part number 681-120 from a large broker of trains and parts, which shall remain nameless--and they sent us 681-121, the ball bearing races. They eventually made good on it, but it was a long wait. In the meantime we ordered the bearing you see in the photos from someone else. (Not sure who, as I didn't do the ordering; this all started while I was visiting over Christmas, and we just recently got it resolved.) Moral of that story, asking for the right thing only helps if your vendor is knowledgeable.

So now, if you find yourself doing this repair, you know what the part number really is, and hopefully you will be able to get the right part right away. The 681-120 rear bearing is definitely correct for this engine, and should be correct for the 681, 682, 671RR, 736, 726RR, and 746, as well as their MPC and LTI clones.

Oh, just one more thing...

My sister's engine is back on the rails, and runs more smoothly and quietly than it did when new. 

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Last edited by Big Jim

As Big Jim wrote, the 671M-20 bearing, with the recessed area, was used in the older motors with loose ball bearings. The part shown in his photograph is a reproduction, machined from solid metal (perhaps its brass). The original Lionel part was an Oilite bearing, which was impregnated with oil.
If you need that bearing, I guess a solid metal one is better than none at all, or a badly worn Oilite one.
The solid metal one might create a little more drag than the original, so I'd keep it properly lubricated.

In case anybody else is wondering: I went through the scan of the article in the linked thread. The issue with the original 18003 motor bearings was the size of their bores. They were made too large (loose).

I did this repair to my Lackawanna loco (so it can't be too hard), but, it has been so long ago I don't remember exactly what all was actually involved. I'm thinking that I had to tap the old bearings out and the new ones were fairly easy to press in.

Does anyone know if the NP version w/Railsounds had the same motor problem or was the problem fixed by the time this one was offered?
NP 4-8-4 edit

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MartyE posted:

Thanks Big Jim.  That is the thread I references and it looks like that post has corrected part numbers.  I'll be seeing if I can get them and make this engine new again.  While it's nothing special it does have some sentimental value to me.

I appreciate the help.

Could you update us with whether the bearings need to be pressed in?  Repair looks like something I could handle but I don't have a press if that is required.  I have the same locomotive and it started locking up a few weeks ago after the kids set it up with a long freight train.  I would like to do the update.  Thank you.

Hi,

I finally picked up one of these at a fair price. It looks like it has some runtime on it and the brass gear looks great with no signs of wear. How would I know if the motor bushings are correct or the incorrect oversize ones? I removed the motor and tried to check for play between the bushing and armature and it seems normal but I also don't want to tear up the brass gear so I was going to replace both motor bushings anyway.  Am I being overly paranoid?

Also the smoke cam on the front axle was broken in half in the well so I'll end up pulling off the front 2 axles to replace that.  I saw 671-182 as the suggested replacement on another post in the form but that is not available. Anyone know if 610-8016-025 would work? It is from the NW 612 J that came out a few years after the 18003.

 

Thanks!

 

Andrew

Hi all.

first thanks to this forum i had the courage to buy a lackawanna 4-8-4 and made the bushing and smoke cam replacements successfully. One question on the motor, is there a stop for how far the front (closest to worm great( bushing pushes into the motor housing? I think i pushed a little too deep as the shaft has a bit too much fore and aft mivement. I was going to tap the bushing out a little but wanted to see if that is correct.

thanks all!!!!

I could not tell if the motor bushing in my lackawanna were good or bad. I compared to a mpc era 611 j which has the same motor and the side play in the worm shaft seemed the same and this lackawanna had mileage on it with no issue running or apparent drive gear wear. I did the bushings to be safe snd the new one has no slop in the drive shaft at all but the shaft spins free so i wonder if my j might have worn bushings. 

Many years ago my Dad made some modifications to his Northern based on the Wabash O1 4-8-4.

C268D038-AE0A-44F9-A7F8-FADA6FCAB915

Unfotunately, after he passed I let it go to auction and regretted not keeping it. Reading this thread inspired me to build one like his, and I was able to finish it today.

F16A8722-DF45-4B97-BF7A-B23EC207BE63

A1D59792-4AA1-402A-92D2-2D937A7A4FFA

I added a steam dome that I found on eBay that fits well.  The only other modifications were to modify the front bell to bend the arm upward and I clipped out the back cab windows for a train crew.

DFAAE28B-B8C5-412B-BE2B-FA3C6EA9F928

The decals were pieced together from various sets I found on eBay as well.  Here is a video of it running:

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Might be a whole lot easier to just replace the whole motor.  I have a spare one I would let go for $45.

Marty

MARTY D.

I have the Lionel Rock Island version of this steamer. I haven't run it much, so the bearing problem hasn't yet emerged. Perhaps it soon will, so I'm interested in your offer to sell the motor - with the bearings problem fixed, I presume.  Got it on hand?  If so, I'll buy it.  Let me know ...

Mike Mottler
22 Water Oak Drive
Conway, AR  72034
501-327-8747
mottlermike10@gmail.com

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