I recently purchased an old Mantua/ Tyco 4-6-2 pacific off eBay. I took it apart, cleaned it, lubed it, etc. The wheels and rods turn perfectly fine by themselves in forward and reverse with no binds whatsoever. I added a very small washer to the motor to make it not have any back/forth play. I tested the motor, and it ran perfectly fine with absolutley no problems. I connected the chassis to the motor, and I had to loosen the motor mount screw to even get the loco moving. I ended up putting a shim so the motor was slightly away from the mount, which made the loco move, but it makes a grinding noise in forward, but is smooth and quiet in reverse. Again, there is little/no back and forth play with the motor shaft, everything is lubed, and all the electrical connections have been checked. Ive been trying to fix this for a while, by doing things like taking out the worm gear and reversing it, moving the worm gear on the shaft, loosening the screw more, and even changing the motor brushes to no prevail. It will always grind when going forward. Can you guys please suggest what I should do to get this loco running smooth? Thanks!
UPDATE: I fixed the issue! I simply switched the old motor out in the locomotive with a motor from one of my Mantua 0-4-0s, and the 4-6-2 is running very smooth & quiet! The funny thing is, the motor from the 4-6-2 also works in the 0-4-0 with no problems for some reason. Thanks for all the replies guys!
This may sound dumb as a box of rocks, but, did it run well before the washer was added to the motor?
If so, I would pull it back out, and try it without said washer.
It just might be something simple, like this, that works as the fix.
Though, I say it it sounds dumb as a box of rocks, as I can't think of any reason that it would be that new washer, other than its the only thing "different" on the locomotive.
Ricky W.
HO scale Proto-freelancer.
My Railroad rules:
1: It's my railroad, my rules.
2: It's for having fun and enjoyment.
3: Any objections, consult above rules.
I'm not a steam loco guy, but it sounds like you should remove what you did to it, thinking you were "fixing" it, like the washer, the shims, etc., and get it back to the way it was before you took it apart.
The cleaning I'm sure did it good, but maybe the extra things didn't?
Mike.
My You Tube
Hexxoid I added a very small washer to the motor to make it not have any back/forth play.
Sounds to me that when you eliminated the motor shaft play you eliminated the ability of the worm to engage the worm gear properly. Remove that washer and see what happens. Sometimes less is not better.
ricktrains4824 This may sound dumb as a box of rocks, but, did it run well before the washer was added to the motor? If so, I would pull it back out, and try it without said washer. It just might be something simple, like this, that works as the fix. Though, I say it it sounds dumb as a box of rocks, as I can't think of any reason that it would be that new washer, other than its the only thing "different" on the locomotive.
Hey, thanks for the reply! I did a decent amount of testing before deciding to add the washer, so the washer actually did help. It's a very thin washer as well. I don't think removing it will make much change.
And no, your reply was not as dumb as a box of rocks. Thanks again!
Now that everyone has suggested I should remove the washer, I'd like to elaborate. The loco still had the grinding problem before I added the washer, so it's not the problem, or at least I don't think. Also, when I really 'hunker down' the motor to the chassis (this is before I added the washer) with the screw, the motor would hum and not turn over because the gears were too tight. Even when the gears are loose, it still grinds. Pushing just the chassis without motor back & forth is smooth as butter, with no problems of any sort. Just thought adding this bit of info would help solve the problem. Thanks for your replies!
I've seen several older steam locomotives where the hole(s) for the screw(s) which hold the motor in place are elongated. This allows you to re-position the motor, fore or aft, relative to the gear on the axle.
As all of those locos seemed to have the motor set-up with its back end higher than the front, moving the motor forward or back will also alter the gear mesh. If the end of the worm is engaging with the worm gear, that may be the cause of the trouble if it's not cut to the full depth like the portion which should be engaging.
Obviously, since moving the motor forward or backward (if it's an option for this loco) will also affect the gear mesh, so you may have to re-shim the motor, too.
I wouldn't remove the thrust washer which you installed unless it actually restricts the motor from turning - end movement within the motor is usually a major source of noise.
Wayne
Another thing'r two to check: When the worm is turning the drive gear forward, it pushes the axle laterally a bit in one direction. In reverse, the other direction. Is it doing so enough to cause the grind? Or, is the worm's position over the drive gear in a neutral position in both directions?
The grind may not be coming from the worm's contact with the driver gear.
You might also check if the grind is coming from the driver gear on the axle rubbing against something if it is being pushed laterally. Look to see if the axle gear is centered on the axle, not able to make any contact with the frame.
If the grind is uneven, like GRRrrrRRRrrrRRRrrr with each rotation of the drivers, check to see if the driver gear is on the axle a little crooked.
The grind could even be a combination of the above conditions.
Just a couple suggestions. Dan
Southgate Another thing'r two to check: When the worm is turning the drive gear forward, it pushes the axle laterally a bit in one direction. In reverse, the other direction. Is it doing so enough to cause the grind? Or, is the worm's position over the drive gear in a neutral position in both directions? The grind may not be coming from the worm's contact with the driver gear. You might also check if the grind is coming from the driver gear on the axle rubbing against something if it is being pushed laterally. Look to see if the axle gear is centered on the axle, not able to make any contact with the frame. If the grind is uneven, like GRRrrrRRRrrrRRRrrr with each rotation of the drivers, check to see if the driver gear is on the axle a little crooked. The grind could even be a combination of the above conditions. Just a couple suggestions. Dan
Thanks for the reply! I took the motor off the chassis and tried to see if the gear could have a possibility of rubbing against the chassis to cause a grinding, and it was 100% smooth, no rubbing. When the loco is running, it's a pretty even grind, just a constant 'grrrrr'. Since the axle is pushed very slightly laterally like you said, I tried pushing it back into the position it would be when going backward, and sort of loosely held it there so I could test if the lateral motion was the problem. The grind still happened.
Heres some pictures:
My first reply was going by your OP, and it sounded like you added the washer, and shimming without trying the loco first.
Thats why I suggested going back to the way it originally came. I didn't realize you had already tried to eliminate thr grinding in previous attempts.
I always thought early Mantua trains were close to, or maybe just a bit above trainset quality. I had a GP20 and it was closer to that type of quality, so I never expected, besides lots of tinkering, it would ever run any better.
After my first Athearn, the GP20 sat in a box.
So, am I wrong? where these good running? or was there a considerable amount of compromise needed while operating?
Your pictures have to somewhere on the internet at a picture hosting site, if you don't have your own domain, and nearly all of us don't.
I suggest Imgur.com, but flickr, imgBB work too. Google and Facebook do not work on this forum. See the stick post in the General Forum
Henry
COB Potomac & Northern
Shenandoah Valley
Once again, I'm not sure if this is a Chrome thing or not, but I right clicked on the picture icon, and opened his photos in a new tab.
I don't see the the picture icon with firefox, but now that you gave me a clue
Hex, right click on your pictures in Flickr and "Copy Image Location"
In this forum click on the picture icon and copy that location with control v
I have one of those. Good locomotive.
Mine has the ordinary el cheapo shim and pray worm to worm gear arrangement. Literature indicates that some of them came with a real gearbox, which ought to work better, but I don't have one and from your post it sounds like you don't either. Gear lash (clearance between worm and worm gear) is critical to proper operation. As a rule, more lash is better, until it gets so wide that the worm begins to skip worm gear teeth under load. You set the gear lash by shimming the motor in the fore and aft direction. You have inspected the worm and worm gear for bad, crunched, or missing teeth, I assume. You might want to check all the wheels for gauge, a mis gauged center driver could pull the worm gear out of proper position. You say the drivers and rod assembly rolls smoothly with the motor out, that eliminates a lot of problems. You say the locomotive won't run at all with th motor screwed down tight, no shims. That says your gear lash is too tight.
My Pacific came with the stock open frame Pittman style motor, which gave very decent slow speed operation. I replaced it with a can motor conversion kit (motor and a mounting bracket) from Mantua's parts operation and obtained even better slow speed operation. Mantua is gone now, but Yard Bird trains carried the can motor kit for quite some time. Might still have some. I have also had excellent performance from antique motors by replacing the old Alnico magnets with the new neodynium super magnets.
David Starr www.newsnorthwoods.blogspot.com
Looks like it's running in a couple of the pictures, too bad it's not a video so that maybe we could hear it.
So, if you didn't see the icon in FF, how did you get to his pictures?
Just eyeballing your photos, it looks to me as if the worm is a little too far forward. You want to have the same amount of worm over the worm gear in both forward and reverse. If the worm is too far forward or backward, you will have teeth on the worm gear striking the long single tooth of the worm.
mbinsewio, if you didn't see the icon in FF, how did you get to his pictures? Mike.
I used chrome, but I did not scroll down to capture the rest of his pics
There are 3 more, but not in good focus. For firefox users they are here
dstarrJust eyeballing your photos, it looks to me as if the worm is a little too far forward.
I was noticing that. On my diesels, the worm is centered over the gears.
mbinsewi My first reply was going by your OP, and it sounded like you added the washer, and shimming without trying the loco first. Thats why I suggested going back to the way it originally came. I didn't realize you had already tried to eliminate thr grinding in previous attempts. I always thought early Mantua trains were close to, or maybe just a bit above trainset quality. I had a GP20 and it was closer to that type of quality, so I never expected, besides lots of tinkering, it would ever run any better. After my first Athearn, the GP20 sat in a box. So, am I wrong? where these good running? or was there a considerable amount of compromise needed while operating? Mike.
I have a few other mantua steamers, and no, most of these locos are above trainset quality. They are mostly metal, can be fitted with can motors if desired, have smooth operating mechanisms (besides this one lol), etc. It's pretty suprising how some of these can withstand quite alot all while still running.
HexxoidI have a few other mantua steamers, and no, most of these locos are above trainset quality
OK, cool, I wasn't sure. I was given a Mahano steam loco, and I was totally surprised how quiet and smooth it runs.
But I digress,
From the pictures, it looks like the motor worm gear is too far forward.
Try reshimming the entire motor to sit further back, as it appears this is definitely a possible issue.
I built one as a kit and had another two bought as basket cases for eventual kitbashes and I got them in running order before other priorities pushed it all aside.
The mesh of worm and gear took tinkering and yes it was not uncommon to have it work wonderfully in one direction but not the other. It was also not uncommon for the worm to be so tight on the gear that nothing moved at all.
Sometimes just removing the motor and reinstalling it would cure everything. Sometimes removing the drivers from their brass bushings held in the frame and moving the bushings around cured everything. Sometimes it would run beautifully upside down but not when on the track (some brass steam has that same affliction). I do not have the engines in front of me but I agree with the recollection that the slot for the screw that holds the motor was elongated suggesting that it was intended to be trial and error and tinkering and moving the mounting in tiny increments.
It was obviously a very fine and even arbitrary adjustment. I seem to recall even the instructions mentioned the possible need to shim. I never tried moving the worm on the shaft and would not suggest it unless all else fails.
All the Mantua steamers I ever had (2-8-2, 0-6-0T, 0-4-0T) had this need to tinker with the interaction of worm and gear
Dave Nelson
Since you had this 4-6-2 all appart, do the axles ride in brass bearings (the Mantua way) or in just a slot (Tyco tried this at one time to save cost - terrible)? Check either of these very close as wear can create slop and noise. When you ran it upside down in test mode with jump wires did the blind wheel driven axle or its gear move in any direction foreward/rearward or side to side? That will create all kinds of sounds. Also, did the drive rods and valve gears remain in their plane? This occurs often requiring tricks to fix. Sometimes with a well placed finger touch you can lesson or stop a bad movement and the sound will change. If all this is okay and the drive gear is in plane at the center of the axle with little wear, something is wrong with the worm gear and motor shaft setup. These old Mantuas are great locos. Do not give up on it - you can fix it. After you get it running, replace the pilot and add some detail castings and piping to the boiler. Who knows, maybe a can motor and DCC are in this Pacific's future. Good Luck!
dstarrJust eyeballing your photos, it looks to me as if the worm is a little too far forward. You want to have the same amount of worm over the worm gear in both forward and reverse. If the worm is too far forward or backward, you will have teeth on the worm gear striking the long single tooth of the worm.
I agree, and that's to what I was referring in my previous post about the end of the worm, where the thread may not be fully-cut, and can't properly mesh with the worm gear.
PeteVSWhich end of the armature did you add the washer to? Testing with the shell off should reveal a slight shift in armature location when direction is changed. I would think that about .010 movement (axial slack in the armature) should be about right. And, there should be a good washer at each end. Does the axial movement of the armature allow the brushes hit a portion of the commutator that's different than the portion where the brushes ride going in the opposite direction? If you take the motor out and run it in both directions, does pressing the spinning armature in either direction along its axis, running in either direction cause a noise or slow down?
I tested the motor beforehand seperate, and it works really nice and smooth, with minimal 'slop' forwards and backwards. The brushes are fine, same with the commutator. I added the washer to the part on the armature closest to the magnet (away from the worm gear).
stevetx Since you had this 4-6-2 all appart, do the axles ride in brass bearings (the Mantua way) or in just a slot (Tyco tried this at one time to save cost - terrible)? Check either of these very close as wear can create slop and noise. When you ran it upside down in test mode with jump wires did the blind wheel driven axle or its gear move in any direction foreward/rearward or side to side? That will create all kinds of sounds. Also, did the drive rods and valve gears remain in their plane? This occurs often requiring tricks to fix. Sometimes with a well placed finger touch you can lesson or stop a bad movement and the sound will change. If all this is okay and the drive gear is in plane at the center of the axle with little wear, something is wrong with the worm gear and motor shaft setup. These old Mantuas are great locos. Do not give up on it - you can fix it. After you get it running, replace the pilot and add some detail castings and piping to the boiler. Who knows, maybe a can motor and DCC are in this Pacific's future. Good Luck!
I guess this is what you're talking about- it doesn't have any brass bearings, as the wheels just kinda sit in the chassis. Even though this is the case, the wheels turn smoothly on their own, as mentioned.
I've been going crazy for a week working on a Mantua 2-8-2 I got off ebay, which ran much better in reverse than forward. Have spent time on forums and tried many of the solutions and noted "they'll do that". I have a bunch of older (and very old ) 4-6-2's w/o similar issues. Was running out of ideas/shims/washers etc. Then I decided to swap it's ATSF 12-wheel tender with a newer Vanderbilt style 12 wheel tender... 100% improvement I'm seeing near equal performance in both directions (I have it on a shuttle track and timing with a stop watch). Anyone ever see anything like this? I know the wheels on the ATSF are pretty squirrely. I then stuck the ATSF onto the back of an Bachmann Loco (doesn't need the tender for power) and it seemed to perform the same in each direction.