MTH 390E Problem

More information- I just tried it again.  This is on STD-72 by the way.  I turned the sounds off and had the engine go around the curve as slow as possible without it stopping.  There is definitely a rhythmic grinding noise only when on the curve.  It sounds like the gears aren't synching up when it goes around right turns.  It will power through the turn if it has enough speed but if I make it go slowly, it will suddenly stop.  I swapped in my other 390E for comparison and it was dead silent around the curve.

I can’t understand how the gears could be binding on only one curve direction. I thought the gears are inside a Bild-a-loco frame and the drivers are fixed. That setup shouldn’t be susceptible to differences in a curve track. Have you checked the front pilot for any binding? Will it go backwards around the curve you are having problems with?

The curve direction could put more stress on the driver wheels on the inside of the curve. I wonder if you have an axel bearing out of place or broken? The axel bearings are a tube with a slot that rides on the frame wall. The axel goes through the tube.

George

George, there is every possibility that my terminology is wrong.  Here is a picture the "gears" I was speculating about.  Yes it will go backwards. Pilot seems fine but I will run it again paying close attention to it.

beachhead2 posted:

George, there is every possibility that my terminology is wrong.  Here is a picture the "gears" I was speculating about.  Yes it will go backwards. Pilot seems fine but I will run it again paying close attention to it.

Ahh, right! I was thinking about the can motor gears inside the motor. Are those gears in your picture on the inside of the curve when you are having trouble? I wonder if the wheels are pressed too tight? It doesn’t really look like it from the picture. I would pop the collector/roller plate off and get a look at how the wheels are set in the frame. Just pull the cotter pins and it should come right off.

George

The gears in the picture are on the outside of the curve when it has trouble.  There is some play in the wheels/gears.  In fact, I was speculating that the play was too sloppy and the gears weren't meshing.  But the other 390E (which is actually the one in the picture) seems the same and it operates flawlessly.  I'll have to have look inside tomorrow.  If I go rummaging around in the Christmas layout, I'm liable to wake my kids.

Take one of the operating locos and measure flange to flange on the drive wheels and then compare to the troublesome loco. There is a chance the wheels are binding in the curve because they are too far apart.

Another thing to check in the process of elimination - try running the loco in reverse going both clockwise and counter-clockwise and see if the problem is consistent with the gears being on the outside of the curve.  This might give a clue. 

Also, a former club member had a similar engine that was making noise.  Took the cover plate off and discovered that the worm gear and axle gear had been grinding each other and there was a nice pile of metal shavings inside the motor.  As I recall, both gears were chewed up.  He sent it back for repair, so I don't know what the cause or ultimate resolution was, but I suspect that the motor was either loose or misaligned in its mounting. 

make sure everything is oiled and lubed, your gears look dry, also take cover plate off and make sure there is grease in the gear box

Lenny J posted:

Take one of the operating locos and measure flange to flange on the drive wheels and then compare to the troublesome loco. There is a chance the wheels are binding in the curve because they are too far apart.

According to my dial calipers, there is less than 1mm difference between any of the four drivers between the two 390E's.

Mallard4468 posted:

Another thing to check in the process of elimination - try running the loco in reverse going both clockwise and counter-clockwise and see if the problem is consistent with the gears being on the outside of the curve.  This might give a clue. 

Also, a former club member had a similar engine that was making noise.  Took the cover plate off and discovered that the worm gear and axle gear had been grinding each other and there was a nice pile of metal shavings inside the motor.  As I recall, both gears were chewed up.  He sent it back for repair, so I don't know what the cause or ultimate resolution was, but I suspect that the motor was either loose or misaligned in its mounting. 

It does run in reverse okay and there is significantly less or no noise.  I took the plate off.  See below.

Popi posted:

make sure everything is oiled and lubed, your gears look dry, also take cover plate off and make sure there is grease in the gear box

To be clear, that first picture is not the loco in question.  Ironically, the drier gears you see in that picture is my other 390E that runs just fine.  Not to worry as it's not in use currently so I'm not running it with dry gears.

As to the offending loco, I popped that bottom plate and here are a couple pictures of the inside gear and pinion (that's what I'm calling it).  There are no metal shavings.  It's not dry but there isn't tons of grease either.  Any thoughts?  My first inclination is to pack it liberally with grease, put it back to together, and give it a whirl.

as a side note, I have one of those locomotives and spun a drive gear. direct from MTH

the gear cost me $35.00. its not a hard change, but if you keep everything greased,

you should not have any problem.

Popi posted:

as a side note, I have one of those locomotives and spun a drive gear. direct from MTH

the gear cost me $35.00. its not a hard change, but if you keep everything greased,

you should not have any problem.

By "spun" do you mean that the gear was totally ground down where it got no bite from the pinion?  What do you think of mine from the pics?  Doesn't seem bad to me but it's the first one I've looked at.

The internal gears look OK. You don't need a lot of grease. What am I seeing here in the gear teeth?

The driver bearings look to be seated correctly and are in good shape. If those gear teeth I circled are OK, you might try removing the side rods and running it without them. I had my side rods off by 1/32" on my original 390e and it didn't run right.

George

Please give us a photo of your motor mounts. There were some of these that were made upside down. If that is the cast than the motor itself could be twisted.

Scott Smith

George S posted:

The internal gears look OK. You don't need a lot of grease. What am I seeing here in the gear teeth?

 

That's just some grease.  I greased it again while I had it on the bench.

George S posted:

try removing the side rods and running it without them. I had my side rods off by 1/32" on my original 390e and it didn't run right.

Okay, I'll try that too.

scott.smith posted:

Please give us a photo of your motor mounts. There were some of these that were made upside down. If that is the cast than the motor itself could be twisted.

Scott, can you tell me where those are?  I would have thought the motor mounts were the four screwheads you see under the pinion in those last two pics.

Interesting! I had a similar problem with an earlier brand new conventional MTH gray 392E. Dealer took it back, and had MTH, at my request, send me direct a traditional version which also crapped out! Ended up with a refund!  😐

I'm not sure what Scott is referring to, but the entire Proto-Drive motor should come out of the engine. Mine had a lever on the front and back that turned 90 degrees to release the engine. The can motor should be mounted on top. The frame on the original motors had a plate on each side that was screwed to spacers.

George

There are two motor mounts and if they look exactly like this one it needs replaced.

scott.smith posted:

There are two motor mounts and if they look exactly like this one it needs replaced.

Please pardon my ignorance, but what are you referring to?

Mallard4468 posted:

scott.smith posted:

There are two motor mounts and if they look exactly like this one it needs replaced.

Please pardon my ignorance, but what are you referring to?

There is one of these at each end,  Two screws have to be undone on this part to get into the motor.

Scott Smith

George S posted:

The internal gears look OK. You don't need a lot of grease. What am I seeing here in the gear teeth?

The driver bearings look to be seated correctly and are in good shape. If those gear teeth I circled are OK, you might try removing the side rods and running it without them. I had my side rods off by 1/32" on my original 390e and it didn't run right.

George

The newer engines I've opened up had a lot more grease on the internal gears.  (Not saying that's correct or necessary, just what I've observed.)  The gear that mates with the worm looks like it has some wear, but hard to tell from the picture.  And the circled spot just looks like grease - the gear on the driver to the left looks similar.

The fact that it runs fine in reverse in either track direction is odd - seems like it should have a problem when the gears are to the outside, just like it does moving forward.

scott.smith posted:

Mallard4468 posted:

scott.smith posted:

There are two motor mounts and if they look exactly like this one it needs replaced.

Please pardon my ignorance, but what are you referring to?

There is one of these at each end,  Two screws have to be undone on this part to get into the motor.

Scott Smith

Right, I recognize those.  However, the comment that if they look like that, they need to be replaced implies that there's something wrong, and I'm not seeing what that problem is.

Mallard4468 posted:

scott.smith posted:

Mallard4468 posted:

scott.smith posted:

There are two motor mounts and if they look exactly like this one it needs replaced.

Please pardon my ignorance, but what are you referring to?

There is one of these at each end,  Two screws have to be undone on this part to get into the motor.

Scott Smith

Right, I recognize those.  However, the comment that if they look like that, they need to be replaced implies that there's something wrong, and I'm not seeing what that problem is.

I believe the correct placement of that part is one screw mounting the lever to the frame of the engine. The lever in the picture is upside down. The hole that is screwed to the brass motor spacer bar should instead be screwed to the engine frame where the flat head screw is located. The flat head screw should be used and the hex screws discarded. The lever then swings over the motor spacer bar to lock the motor into the engine. It's basically a locking device.

George

George S posted:

Mallard4468 posted:

scott.smith posted:

Mallard4468 posted:

scott.smith posted:

There are two motor mounts and if they look exactly like this one it needs replaced.

Please pardon my ignorance, but what are you referring to?

There is one of these at each end,  Two screws have to be undone on this part to get into the motor.

Scott Smith

Right, I recognize those.  However, the comment that if they look like that, they need to be replaced implies that there's something wrong, and I'm not seeing what that problem is.

I believe the correct placement of that part is one screw mounting the lever to the frame of the engine. The lever in the picture is upside down. The hole that is screwed to the brass motor spacer bar should instead be screwed to the engine frame where the flat head screw is located. The flat head screw should be used and the hex screws discarded. The lever then swings over the motor spacer bar to lock the motor into the engine. It's basically a locking device.

George

Exactly, they were made upside down. They don't hold the motor in correctly causing kinds of issues.

Scott Smith

Here are the motor mounts...

I'm unsure if these motor mounts are a problem.  They aren't exactly the same as your picture so I hope not.

George S posted:

Mallard4468 posted:

scott.smith posted:

Mallard4468 posted:

scott.smith posted:

There are two motor mounts and if they look exactly like this one it needs replaced.

Please pardon my ignorance, but what are you referring to?

There is one of these at each end,  Two screws have to be undone on this part to get into the motor.

Scott Smith

Right, I recognize those.  However, the comment that if they look like that, they need to be replaced implies that there's something wrong, and I'm not seeing what that problem is.

I believe the correct placement of that part is one screw mounting the lever to the frame of the engine. The lever in the picture is upside down. The hole that is screwed to the brass motor spacer bar should instead be screwed to the engine frame where the flat head screw is located. The flat head screw should be used and the hex screws discarded. The lever then swings over the motor spacer bar to lock the motor into the engine. It's basically a locking device.

George

Thanks for the clarification.

beachhead2 posted:

I'm unsure if these motor mounts are a problem.  They aren't exactly the same as your picture so I hope not.

It looks like your motor mounts are fine. I haven’t seen them screwed in, but it seems that was intended.

George

George S posted:

beachhead2 posted:

I'm unsure if these motor mounts are a problem.  They aren't exactly the same as your picture so I hope not.

It looks like your motor mounts are fine. I haven’t seen them screwed in, but it seems that was intended.

George

I think the majority of mine have the screws to lock the motor in place.

Steve

Steve "Papa" Eastman posted:

George S posted:

beachhead2 posted:

I'm unsure if these motor mounts are a problem.  They aren't exactly the same as your picture so I hope not.

It looks like your motor mounts are fine. I haven’t seen them screwed in, but it seems that was intended.

George

I think the majority of mine have the screws to lock the motor in place.

Steve

Must be on the newer ones. My 400e PS2’s and my original 390e don’t have them.

George

Update - I really loaded it up with grease and put the bottom plate back on.  I left everything else off.  I ran it around quite a bit and it went well.  It did not hang up no matter how slow.  And just as important, it isn't making noise.  Makes me wonder what the issue is/was but for now I'm happy.  Seems likely that the gears on the inside or outside (or both) want a lot of grease.  So now I'll hit them again, put the drivers and trucks back on, and see what happens.

beachhead2 posted:

Here are the motor mounts...

Your motor mounts are fine.

Scott Smith

beachhead2 posted:

Update - I really loaded it up with grease and put the bottom plate back on.  I left everything else off.  I ran it around quite a bit and it went well.  It did not hang up no matter how slow.  And just as important, it isn't making noise.  Makes me wonder what the issue is/was but for now I'm happy.  Seems likely that the gears on the inside or outside (or both) want a lot of grease.  So now I'll hit them again, put the drivers and trucks back on, and see what happens.

You took the siderods off? I bet that was the issue. If it happens again, check each linkage right at the spot when it stops and see if any one of them is tight or obstructed. Grease can’t hurt. It will certainly make it quieter. It even could have been a slight misalignment of the roller plate on the bottom.

Glad it’s working!

George

George S posted:

You took the siderods off?

Yes, I said drivers.  I meant the siderods.  I'm totally stumped because I found nothing but it is okay now.  I really hate when that happens.  We'll see.  Thanks for your help everyone.

I realize it's an MTH with different gearing, but after reading everything folks wrote, especially Georges comments about taking off the side rods it reminded me of a similar problem I had with a 260e. Ran great in one direction and reverse but slowed and ground on curves in the other direction. Drove me nuts until I finally found one of the drive wheels was slipping slightly on the axle. A new MTH shouldn't do that but it might be worth a look...?

Make sure set screws are tight on gears.. Mine were loose.  Don't care for that design.