MTH PS2 400e slipping gears - help

It's a common issue, the brass gear has gotten chewed up.  I think Henning's has the gears in stock, I used my last one recently.  The old gear may either be pressed on or have a set screw.  It's usually fairly easy to swap them out and put the new gear in.

I've seen this before but in the O scale line. More than likley either worm gear on the motor and or the drive gear that mates with that worm gear on the motor is completely destroyed and stripped. No teeth left. Getting those parts from MTH you'll end up having to buy the whole drive block. This is based on what we had to do as a dealer/service station. If you are lucky you might be able to buy just that part of the drive shaft with the gear. 

 If you say that it's not chewed up then that drive gear might be slipping on the shaft. 

I've replaced these gears a few times in the STD gauge stuff, the gears were available, and I know Henning's had some a few months ago.  The motor has a steel worm, the drive block has a brass gear.  The brass gear loses.

If it's not chewed up, maybe the setscrew is loose, that would be the cheap fix.

gunrunnerjohn posted:

I've replaced these gears a few times in the STD gauge stuff, the gears were available, and I know Henning's had some a few months ago.  The motor has a steel worm, the drive block has a brass gear.  The brass gear loses.

If it's not chewed up, maybe the setscrew is loose, that would be the cheap fix.

Thank you. It didn't look chewed up. I'll open it back up and take a look. Those are easier to get to than pulling the whole motor.  Maybe it's the set screw... It could be, because this seems to happen only when a little torque is needed. 

George

G. I've never run mine. But that gear is loose. A. Set screw. I think one on axle.  Can't remember if the outside one has one or not.

You might want to see if that axle has a flat for set screw. If not add one.  Or drill a hole for set screw.

Thanks Riki and Bruk.

I had a piper with the same problem,,,,it was an easy fix,,,,(which I didn't do)

The gear is: EG-0000021, and the whole shaft is TP-SL00171 which includes the gear.

The gear is on the common parts list, that's how often it needs replacing!

Thanks John. I just ordered it from Hennings. Man, I can hardly see where it’s bad. It’s on one side of the gear. I took the set screw out and moved the gear to the other side of the drive and it’s fine. Only thing is, the set screw screws into the shaft, locking into position, so it needs a new gear.

Blow up the second picture and you can see the flat spot. If both gears were steel, we’d be replacing can motors. So, this is the lesser of evils.

George

Yep, that's why they're so often replaced.   I've seen enough of these to go for that gear first.

Thanks again. I'll post pictures of the repair for others to see. It should be pretty easy.

George

3d guys could make them out of nylon. Or delrin. That brass. Seems not to handle it.

Unless the set screw works loose then the wear starts.

Maybe lock tight.  It.

George, can you link to that part on Hennings?  I looked and I can't find it.  Thanks.

https://hennings-trains.shopli...r-axle-gear-mth.html

riki posted:

https://hennings-trains.shopli...r-axle-gear-mth.html

Excellent.  Thanks. 

Don’t buy them all. I have another 400e that I haven’t tested.

George

Waiting on the gear but decided to start disassembly. You need to take the drive wheels off to move the drive shaft, to get the brass gear off.

George

Sure, but the wheels just "drop out", you don't have to do anything special.

G. Was the gear snug on axle?. And how long is set screw.

riki posted:

G. Was the gear snug on axle?. And how long is set screw.

The gear was snug. The set screw is not long, maybe a quarter inch. It screws into the axle.

gunrunnerjohn posted:

Sure, but the wheels just "drop out", you don't have to do anything special.

Yep. Actually, one didn't want to come out for some reason. When putting them back in, it's important to line up the side-rods to prevent binding. I know you know this John but just adding details for others who may not be as experienced.

George

G. I guess it's together. But I think I would get a 1/2 or longer set screw. To make sure it goes thru axle. And out other side. Then it's locked in.

Well, my first attempt failed. I got the gear and put it all together correctly. The gear came with a longer screw to go all the way through the axle, but it didn't fit. I tried it with the shorter screw, but there was some play and the gears slipped. I tried to put the long screw in again, but I forced it and broke it off in the axle. While I was able to drill it out, I am going to buy an assembly. I think the issue might be that I have a Tinplate Traditions 400e, and these parts are made for the newer engines. While it should still work, I think there may have been tweaks to the design. One thing I noticed when I had it together was that everything seemed to line up better than the old gear did. Anyway, I'm ordering the new parts.

George

Correction: I can't find the assembly to order. I may need to get a screw and tap the shaft.

Bruk posted:

I've seen this before but in the O scale line. More than likley either worm gear on the motor and or the drive gear that mates with that worm gear on the motor is completely destroyed and stripped. No teeth left. Getting those parts from MTH you'll end up having to buy the whole drive block. This is based on what we had to do as a dealer/service station. If you are lucky you might be able to buy just that part of the drive shaft with the gear. 

 If you say that it's not chewed up then that drive gear might be slipping on the shaft. 

MtH now has replacement gearsets for the O-gauge tinplate motors.  If the worm driven gear is not retained by a setscrew, cut the shaft and remove the old gear assembly.  You can buy just the worm driven gear or the entire assembly (worm driven gear, shaft and idler.  Don't have the part numbers handy, but Deb has them.

I've always just bought the gear, I've had one O-gauge one a while back, and a few std-gauge ones, std-gauge seems to eat gears.

On the 400E and all tinplate locos with Protodrive, there are about 5 variations on how that gear assembly is made (yeah, it's a pain).  You have to get the mesh just right.  Not too tight and not too loose or it will chew it up.  The factory put thin washers between the motor and motor mount on some locos (real fun to get them in there; grease helps holding them in place) to tilt the motor in order to get the right mesh.  It's a trial and error approach.  As for centering the gear on the worm, you can play with shims on the crossshaft between the idler gear and stop collar.

The gear is sacrificial, so keep it lubed well, especially if pulling heavy loads.  While you have it open, put a drop of oil on the striped flywheel bearings.  That sucker spins fast and the bearings will wear out causing you to lose speed control.

George, I have seen this problem on a recent repair, but replacing the gear won't solve the problem- completely.

The engine I worked on had such POOR mesh between the motor and the gear that it would skip. In order to fix it once and for all, I had to remove the motor mount from the frame, drill the mounting holes in the frame to a larger drill size, then I could re-install the motor mount and push it closer so that the worm and worm wheel would mesh completely. Without opening up those holes, I could not get the mesh right.

Very poor workmanship on these motors, and a guarantee of a redo if you don't get them meshed right.

Jim

Jim Waterman posted:

George, I have seen this problem on a recent repair, but replacing the gear won't solve the problem- completely.

The engine I worked on had such POOR mesh between the motor and the gear that it would skip. In order to fix it once and for all, I had to remove the motor mount from the frame, drill the mounting holes in the frame to a larger drill size, then I could re-install the motor mount and push it closer so that the worm and worm wheel would mesh completely. Without opening up those holes, I could not get the mesh right.

Very poor workmanship on these motors, and a guarantee of a redo if you don't get them meshed right.

Jim

Thanks for posting this here Jim. You and I have been exchanging messages about it offline. It will be helpful for anyone following along to know this. That is exactly the problem I had when I put it back together. I'll post results once I get to this.

George

Thanks Jim

Whenever I get to mine I'll check it.  That motor is what I was going to modify for my Hudson. Guess I'll make my own drive .

Yesterday, I unscrewed the motor mounts from the frame. There are six screws, four on one side and two on the other. I also unscrewed the motor from the motor mount. The motor was shimmed on one side, but not nearly enough. I removed the shims and reattached the motor to the mount. The motor and mount can only move a little bit in the frame, but that seems to be just enough. I was able tilt the motor, more than slide it, but I achieved a very nice mesh. I then checked the frame holes, which I will be drilling out (making oblong). The screw holes need to move about half the width of the screw, so not very much. One odd thing was that the two screws in front still seem to be centered. I don't really understand that. Maybe the motor mount is warped due to poor manufacturing alignment? 

I need to disassemble everything to drill out the frame. I don't want metal filings anywhere near the engine electronics, speaker or mechanicals. I'll mark it first. More to come.

George

WHEW! Sounds complex due to flawed design! GOOD LUCK! Just glad I only have traditional MTH BAL motors to deal with at this point! 

They have issues too.  Sometimes jam in one direction because the armature is not centered in the field.  I fix them on my metal lathe.

Guess I have just been lucky, but I have never had an issue with any MTH or Lionel Classics BAL motor with well over a dozen engines. My current ones are early Chinese production (2000) and Korean (1990) - likely better quality?

Samhongsa was the "gold standard" tinplate manufacturer for MTH and my present dark grey 2-400E runs smooth as silk. Interestingly, the tender has an unlisted (on the box label) diecast whistle and my previous one back in 1990 also had one, so I am pretty certain it was not a mod. My second and present one came factory sealed from Grzyboski's, a VERY reputable dealer!

I got it running but have one more problem to troubleshoot. Using Jim Waterman’s fix, I drilled out the 6 holes in the frame for the motor mount and tilted the motor toward the brass gear.

I got a good mesh that wasn’t too tight. It runs good in both directions. I have smoke and speed control but no sound or lights. I tried an engine reset but that didn’t help. I guess one of the wire harnesses on the PS2 board came loose. Would like to hear if that sounds correct before I open her back up.

George

Holy cow George, that seems like a Peta for such an expensive engine?

@John H. Shetler posted:

Holy cow George, that seems like a Peta for such an expensive engine?

Yep. Although I bought it used for half what the new ones cost. She ran great for several years. I think some of my track separated, because I hadn’t screwed it all down yet, and that hung the cars up. That’s when the gear stripped.

George

Glad to hear it worked for you George.

Jim

I fixed the sound and lights today. Everything works. The wiring harness had pulled out of the socket when I had it apart. I couldn’t see it until I looked for it.

George