Lionel JLC Allegheny #1650

@Secarider posted:

When the locomotive is running, the front drive shaft hops up and down a lot, and makes noise. This is not normal operation. This locomotive was bought by my Son brand new from Trainz. He finished his layout, and this was the first time we could run it on 072 curves. The wheels, the tires and collector rollers did not show any signs of being used, when we took it out of the box.  So if the front drive was removed by someone, and streached the rubber tubes it was still not run on the rails until last night. I was hoping that maybe some one had these same issues, and knew how to correct it. I will check the brakes to be sure that they are not rubbing on the tires and causing the front wheels to bind and make the drive shaft hop up and down. Thank you all so much for your advice.

Sorry to dig up an old post, but I’m wondering if you ever figured this out? I just bought the same locomotive with the same exact issue. Smooth as silk in reverse but in forward the front gearbox chatters. Just got it tonight so haven’t taken anything apart other than the bottom cover of the front gearbox to check lube.

My son paid so much money for it, I did not want to be responsible to work on it. I ended up buying it from him. I was going to remove the cover, and use Labelle 106 grease on it.  These JLC locomotives are nice. But the detail is so fragile, its hard to handle it and work on it without breaking something. I would try to get help handling it, and turning it upside down. Pay attention to detail, and use folded dish towels on solid areas of the boiler to keep weight off fragile areas. If you remove the body do it very carefully and slowly.  Unplug  things as you go along. Do not stress and break the antenna wire especially. Do not grab the sides of the boiler or you will surely start breaking plastic mounts for the pipe detail. One inside welcome to my nightmare. Very difficult to remove all the wire and electronics to get to the drive shafts and gear box. I worked on a used one,and our spare parts one. Mine new one is buried in the closet.  Let me know how you make out. Also if the tender chains are not already broken,do not turn the wheel trucks very far. They were made for O72 or larger curves, the chains will snap. Good luck

@Secarider posted:

My son paid so much money for it, I did not want to be responsible to work on it. I ended up buying it from him. I was going to remove the cover, and use Labelle 106 grease on it.  These JLC locomotives are nice. But the detail is so fragile, its hard to handle it and work on it without breaking something. I would try to get help handling it, and turning it upside down. Pay attention to detail, and use folded dish towels on solid areas of the boiler to keep weight off fragile areas. If you remove the body do it very carefully and slowly.  Unplug  things as you go along. Do not stress and break the antenna wire especially. Do not grab the sides of the boiler or you will surely start breaking plastic mounts for the pipe detail. One inside welcome to my nightmare. Very difficult to remove all the wire and electronics to get to the drive shafts and gear box. I worked on a used one,and our spare parts one. Mine new one is buried in the closet.  Let me know how you make out. Also if the tender chains are not already broken,do not turn the wheel trucks very far. They were made for O72 or larger curves, the chains will snap. Good luck

Thanks for the advice. Watching it operate at 1mph in forward I can clearly see the front gearbox hop up and down and it is clearly designed the way Norm states above. I think I’ll try it with a lid first and then maybe come up with a way to cushion or dampen the gearbox. Nothing appears to be “broken”, it just looks like excess slop.

Mine doesn't do this. When I've worked on my dad's brass HO engines, the hopping tends to be because the screws on the gearbox have loosened. Maybe check if that is the issue. Taking the engine apart is not too hard, at least when I did it in mine (just 4 screws to remove). The only fragile part were the wires connected to the hands rails as the antenna.

Another possible issue is if the wheels/rods are not quartered which is strain on the wheel turns that could cause the hop with the engine trying to roll the wheels.

@C&O Allan posted:

Mine doesn't do this. When I've worked on my dad's brass HO engines, the hopping tends to be because the screws on the gearbox have loosened. Maybe check if that is the issue. Taking the engine apart is not too hard, at least when I did it in mine (just 4 screws to remove). The only fragile part were the wires connected to the hands rails as the antenna.

Another possible issue is if the wheels/rods are not quartered which is strain on the wheel turns that could cause the hop with the engine trying to roll the wheels.

I thought about the timing of the rods but kind of dismissed it as it is absolutely smooth in reverse. Reverse is where the front gearbox is pushing down on its nose and the driveshaft is straightest. In reverse, the nose lifts and the angle of the shaft may be too much making it bind but I'm not sure yet. The gearbox is tight (I opened it to lube it), so i think my first step will be shimming the nose to reduce the amount the nose can rise. Could simply be manufacturing tolerances in the 'floating' gearbox on the front.

@David K. Simpson posted:

I thought about the timing of the rods but kind of dismissed it as it is absolutely smooth in reverse. Reverse is where the front gearbox is pushing down on its nose and the driveshaft is straightest. In reverse, the nose lifts and the angle of the shaft may be too much making it bind but I'm not sure yet. The gearbox is tight (I opened it to lube it), so i think my first step will be shimming the nose to reduce the amount the nose can rise. Could simply be manufacturing tolerances in the 'floating' gearbox on the front.

I don't think it's likely that the drivers are out of quarter, but I will say that you can see problems in one direction if they are.  I have a JLC Allegheny, I see no issues in either direction, so it's certainly not universal.

My suspicion would be looking at the driveshaft dogbone, those are sometimes an issue.

@gunrunnerjohn posted:

I don't think it's likely that the drivers are out of quarter, but I will say that you can see problems in one direction if they are.  I have a JLC Allegheny, I see no issues in either direction, so it's certainly not universal.

My suspicion would be looking at the driveshaft dogbone, those are sometimes an issue.

I plan on doing a bunch of testing and experimenting this weekend. I know I kind of hijacked this thread but hopefully it helps with future searches having it all in one place. Didn’t seem worth it to start over with a new thread.

There's probably nothing wrong with that engine at all. My now-gone JLC Allegheny was a fantastic runner. Unloaded geartrains can tend to float/hunt around or about it's most free axis (axial in this case). Unless the engine is stalling out/binding, there's probably nothing broken or out of alignment. You would be able to measure that by motor current. If the gearbox was moving in a purely vertical axis, then something is very wrong mechanically. It's not outside the realm, especially if the engine was acquired secondhand. It's amazing what PO's can do a train.

I recommend observing the behaviors under load.

@Norm Charbonneau posted:

There's probably nothing wrong with that engine at all. My now-gone JLC Allegheny was a fantastic runner. Unloaded geartrains can tend to float/hunt around or about it's most free axis (axial in this case). Unless the engine is stalling out/binding, there's probably nothing broken or out of alignment. You would be able to measure that by motor current. If the gearbox was moving in a purely vertical axis, then something is very wrong mechanically. It's not outside the realm, especially if the engine was acquired secondhand. It's amazing what PO's can do a train.

I recommend observing the behaviors under load.

Based on your comments before, that was going to be the first “test” as nothing seems bound up. I plan on trying it under load and seeing what happens. Manufacturing tolerances probably make it a more pronounced issue in some than others I would guess.

Those older JLCs were interesting in that they built with a combination of sprung and fixed axles and floated and fixed gearboxes. The front gearbox being unrestrained (maybe a better term than 'floated') will tend to wind up under load as the worm engages the axle gear. Being that the front universal is a slip coupling, you can imagine the front gearbox is very free about the axle. You may want to look closely at which axles were actually sprung vs. fixed, you may find it interesting. I think the rear gearbox is fixed much like a traditional diecast engine.

For comparison, the new Class A has fixed gearboxes front and rear and all axles are fixed. Not sure what changes Lionel did to the Allegheny when they made the Legacy version of the JLC. I will get another Allegheny when Lionel offers it again since I miss my JLC and I've acquired a couple proper cabooses in C&O.

@Norm Charbonneau posted:

Those older JLCs were interesting in that they built with a combination of sprung and fixed axles and floated and fixed gearboxes. The front gearbox being unrestrained (maybe a better term than 'floated') will tend to wind up under load as the worm engages the axle gear. Being that the front universal is a slip coupling, you can imagine the front gearbox is very free about the axle. You may want to look closely at which axles were actually sprung vs. fixed, you may find it interesting. I think the rear gearbox is fixed much like a traditional diecast engine.

For comparison, the new Class A has fixed gearboxes front and rear and all axles are fixed. Not sure what changes Lionel did to the Allegheny when they made the Legacy version of the JLC. I will get another Allegheny when Lionel offers it again since I miss my JLC and I've acquired a couple proper cabooses in C&O.

Looking at it last night I found it quite a bit interesting. As you say, the rear is fixed and the front floats quite freely. One experiment will probably be a tiny piece of foam to act as a spring pack on a real loco to take some of that movement away. The more I look at it though the more I agree with you that there is nothing “wrong”.

So I‘ve learned 2 things tonight…

If you apply any amount of load , as Norm suggested, the “issue” goes away. Light engine is the only time the front gearbox dances around.

if you put a tiny piece of foam between the gearbox and it’s upper “stop”, the issue completely goes away. Very soft foam, so not enough to stop movement in case of shock, but enough to dampen the oscillation.

Thanks for the feedback and input guys. I’m considering this case closed (for me at least).