Jerky Lionel SD70ACe

does the headlight flicker when it does the " jerky at low speeds"?

 

Nope. No flickering.

Hi Matt,

Did something get caught up in the gears?

 

How do the wheels of the front truck look? Any crud build up?

 

I am thinking that a wheel cleaning may in order if it's a favorite runner of yours.

 

A reset may be in order. Consult the manual for steps. I didn't see the manual on the Lionel product page. Perhaps reassigning the eng id would help.

 

That should rule out some common annoyances.

 

Then you can consider the motor, a slipping gear on the motor shaft, a wheel axle\gear that got funny. I haven't heard of encoder rings coming loose on the flywheel, but who knows? 

 

Finally, try switching the smoke switch on the engine to off. The noise may be a smoke unit fan motor and separate from the jerky movement problem.

 

 

I didn't see anything in the gearing for the most part other then a little bit of lubricant build up, which I wiped away.

 

That was my thoughts too that something like some fuzz or dirt built up in there, but I didn't see any.

 

I tried a reset. That didn't work. Maybe when I get home from work later I'll try assigning it to a new number and see what that does.

 

I was running the engine with the smoke off, so I already ruled out the smoke unit making the noise.

Did you try rotating the flywheels slowly on each truck and feeling for any binding?  That's one of the first things I'd try.  Check the wiring carefully for any breaks.

 

Next, try suspending the engine from the center tank with the wheels free and running it on the bench with a transformer at slow speed.  See if you see any jerking or uneven running for either truck.  Usually, the motor with the encoder will start first with no load, as it's a closed loop.  As you slowly increase the voltage, the other one should run.  If it doesn't run smoothly, you may have a bad motor or gearing.

OK I tried rotating the flywheels by hand on each truck and they moved fine. No binding.

 

Next I lifted the engine from the center tank. When the back wheels were lifted the flywheel spun without any issue but the front jerked a bit and made a squeak noise as it tried to move along. When I had the front lifted the back flywheel spun without any issue. I'm guessing the front flywheel is the issue and since I still have my year warranty I will send it into Lionel for repairs.

Sounds like something in the right truck or motor is indeed the issue.

Hi Matt: before you pack the engine up and send it back to Lionel, have you checked the traction tires?  That's the first thing that comes to my mind every time I hear "jerky" running and a Lionel engine in the same sentence. 

There was a stretch of time where Lionel was using overly-thick traction tires (not sure if they still are).  They have a tendency to rub against the truck side frames causing a jerky condition similar to what you described.  Sometimes it happens right out of the box, and sometimes after running for a while as the extra thick tires begin to flatten out a bit. 

I had to replace all the traction tires on the last two Lionel Legacy diesels I purchased with MTH tires...and I know others have posted here about the same issue.  It's worth a look anyway.

Thanks Joey,

 

I'll look them over again. Maybe one of them is of them is worn and I missed it. 

Good point on the tires Joe, I forgot to mention that.  Typically, I see them rubbing on the dummy brake shoes and causing the friction on steamers.  I have seen issues with diesels as well, I replace them with MTH tires which are much thinner.

 

So I ran the engine without the traction tires on and with the new ones on as well.. Still is jerky. I was really hoping that would have fixed it. Guess I need to send it out. Thanks guys for the help.  Greatly appreciated.

How does it run with the odessy turned off?

did you take the truck off and inspect it very close?

With it turned off it runs smooth. There is a trade off though, it takes longer for me to move it out as opposed to turning the controller and it going.

Yes. No obstructions and thoroughly greased. No frayed wires.

First of all, Lionel's service dept. will talk to you on the phone. They have helped me a few times. I'm not sure if the NC move will affect service contacts in the way it has

temporarily affected parts ordering, but I doubt it. 

 

Secondly, as you turned off Odyssey and had smooth operation, and I had a "jerky"

Lionel 2-8-2 years ago - Odyssey problem - it seems that we may have narrowed the

problem down.

 

Remove the shell and take a look around; pay attention to any tach reader on a

motor flywheel. A loose reader/sensor/flywheel (check for a set screw) could cause

both the jerk and the noise. No? Call Lionel before you mail anything.

 

If this loco has the new ERR tach-less cruise there will be no tachometer reader.

 

It probably has something to do with the tach reader on the motor. Since it is a Lionel factory loco it will not have the ERR board installed. If you are planning an adventure in the shell of your locomotive you must ask yourself "am I comfortable playing around in small spaces with electronic boards and lots of wires"? If you are not familiar or comfortable I suggest sending it back to Lionel for service. Inside an O gauge locomotive can be very intimidating for the unfamiliar, there is a lot going on under there and it is easy to pinch a ire or pull a connection loose and one can do significant damage

Yeah I'm just going to send it back and have them look at it. If I didn't have the warranty I might consider doing it myself, but since I do I might as well use it. This way if they screw up it's covered.