6557 Caboose Issue

Here are some further details, if anyone might be able to make a suggestion:

I noticed that if I had the trains going at a slow speed, they could go 4-5 laps around the oval before the roller problem would occur and I would need to give the roller a light press so it could spring back into position. Bumping up the voltage, the issue would happen before one complete lap.

I then discovered the problem is occurring at one specific spot--right where it exits the paper mache tunnel at one end (of course this is the most inaccessible area in the corner behind the Xmas tree). I squeezed back there and spent some time "erasing" that area of track as best I could with the track eraser that's intended for this purpose. The train will make the loop a few times, but inevitably the caboose will kick up a large spark when passing over this area and the roller will get fused against the rivet/housing above it. The top of the track is perfectly clean and oxidation-free, however. Weird!

Might I have to unscrew all the track sections in this area from the homasote bedding and clean the prongs that connect the tracks? Could oxidation on the prong connectors cause sparking when the train passes over?

Has the insulation on the wire to the roller petrified?  It may need to be replaced with super flex wire.   Best stuff to use on problem electrical connections is electrical spray material Deoxit D5.  It works really good on roller pins and it would probably help with the sticking rivet problem.  

As stated above, check that the pickup wire is in good condition and extremely playable. Deoxit or CRC 2-26 are great for keeping the rollers rolling. Also be sure that the plastic tabs (enclosed in red) are not broken.

The easiest repair would be to replace the whole 481-10 base plate should you find a defect in the pickup assembly.

Hello and thank you: I can confirm that nothing appears to be broken off and the wires are not too stiff, though I do not have any deoxit. Can we rule out a track issue being the culprit, even though the problem keeps happening in the same exact spot?

Thanks again!

Well, if it is sparking and "fusing", something is likely shorting out. If it is happening in the track section consistently, it can't hurt to really examine that areas track work, especially since inspection of the pickup assembly didn't turn anything up. Make sure the rails at the track joints are smooth and that the junction is flat and just generally well laid.

You might even just want to slowly roll the caboose over that area by hand with a real close eye on things to see if you can determine what is happening.

Upon further review...you gentlemen may be 100% correct in your assessment. It does look like the two ends are not symmetrical. If this is in fact causing the problem, I would have to purchase a 481-10 base? Does this require a special rivet gun to install, in which case the repair would be above my pay grade? Thanks again.

Yup, I see a missing plastic tab. That will allow the roller to short. As I said before, replacing he 481-10 base plate is the easy fix.

Thank you for your kind assistance, Mr Moran. Looking on the internet, I see there is a 481-10 and a 481-10t. To confirm, it is the 481-10 I'm after?

I'm not sure how this might have happened, but it's a relief to know it's an easy fix for the layman. Thank you once more.

I believe the distinction most part dealers use between the 481-10 and 481-10T is if the coupler arm is tabbed or not.

Is this the item? It does say "with tab." Do I simply need to remove the horseshoe-shaped clip to make the swap?

https://www.ebay.com/itm/31238...a:g:QfkAAOSwhMFXkkfJ

Here is a write up that discussed base plate replacement: https://ogrforum.ogaugerr.com/...9#157406523756106139

@Desert Center CA posted:

Is this the item? It does say "with tab." Do I simply need to remove the horseshoe-shaped clip to make the swap?

https://www.ebay.com/itm/31238...a:g:QfkAAOSwhMFXkkfJ

That one will work fine, but if the tabs are already bent over the axle like the one in the pic, don't unbend them. It's much easier & faster(about 90 seconds max) to remove the entire old baseplate with wheels & axles from the sideframes & bolster to effect a swap of the wheels & axles to the new baseplate, and pop it back in.

Thanks Rob, but I'm afraid I'm not following what you're advising...

@Desert Center CA posted:

Thanks Rob, but I'm afraid I'm not following what you're advising...

He is just using extra verbiage to cover what I already pointed you to before, specifically highlighted, but in your case, you don't need to concern yourself too much with it, especially because you are not attempting to reuse a base plate which I again highlighted in my previously recommended write up. Also, no new base plate will come with the axle tabs pre-bent, and don't see that in the picture accompanying your auction site listing.

@bmoran4 posted:

Let us reference this parts exploded view:

Replacing the Pickup Assembly - You remove (drill out) the 480-19 rivet releasing the existing 481-6 pickup roller assembly. Access to do this operation requires removal of the 482-3 or 481-10 coupler base plate which is held on by metal tabs wrapped around the axles. You carefully bend the tabs minimally to release the plate or you can gently spread the bolsters to drop the axles out releasing the base plate. The tabs can break, the bolsters loosen, and the repair quality can suffer. You also will need to de-solder the pickup wire or cut it off from the existing pickup assembly. Now, you take your new 481-6 pickup roller assembly and use your new 480-19 rivet to install to the base plate. This requires a rivet setting tool such as Brakeman's Riveter or the Arbor press with the appropriate Lionel or Hobby House dies. Yeah, a punch may do it, but not as cleanly and nicely. Solder the pickup wire to the pickup assembly and reinstall the base plate.

Replacing the Coupler Base Plate - Just like above, you release the old base plate by bending the metal tabs, but since you have a new 482-3 or 481-10 base plate, it doesn't matter if one or more of the tabs break off. Use pliers to bend the tabs of the new base plate around the axles.

Replacing the Truck - Replacing the truck as a whole works well. I believe the 746W tender uses the 482-1 truck in the front and the 481-1 in the rear. Remove the shell and loosen the whistle from the frame to gain access to the truck studs that are held in place with the 480-18 horseshoe clips. Use pliers or a screwdriver to remove the clips to drop the trucks out. Be sure to order new 480-18 clips in the event the existing one are mangled on removal. De-solder or cut the pickup wires from the old pickup assembly. Solder the wires to the new trucks and install the trucks to the frame with new or reused 480-18 clips. Refasten the whistle to the frame. Reinstall the shell.

I generally go with the last two repair methods as the parts are inexpensive enough compared to the time it takes and risks of getting stuck due to causing more damage.

https://ogrforum.ogaugerr.com/...9#157406523756106139

Thank you for the clarification--seems like it should be straightforward enough. I was worried I would have to drill out and use rivets.

Incidentally, what may have caused one of the two little "tabs" as you call them to have broken off, and how does the absence of that small bit  of plastic cause the roller to fuse against the rivet above it when it passes one specific section of track? I realized I do have one other old caboose in the closet that has a light in it, and I ran that one last night to see what would happen. It lit up fine with no issues after @25 passes around the oval loop, and this would demonstrate that the tab piece breaking on the 6557 plate assembly wasn't caused by the track.

Also, I was curiously surprised at the few number of options I found on the internet to buy a 481-10 base plate, as opposed to the more readily-available 481-10t. I decided I like the coupler without the tab better--none of my other trains have them--and so I went with a 481-10.

The broken plastic tab keeps the pickup roller in position so it can't short out against neighboring metal parts of the truck. With it missing, the pickup roller has a larger range of movement and can then short out creating the pitted weld marks on the pickup roller. This shorted current can also weld the rivet in similar fashion.

Most often, I see this type of failure attributed to some sort of mishandling or poor storage, but sometimes a particular gnarly derailment can tweak or trap the roller really badly, say in a switch frog or between rails.

Bottom line, it isn't the end of the world and a fairly easy fix.

@Desert Center CA posted:

Thanks Rob, but I'm afraid I'm not following what you're advising...

It looked like the pictured part already had the tabs  bent, it doesn't.

Don't ever un-bend any tabs.  Remove / service baseplates w/o bending tabs as they fatigue very quickly with repeated bending.

@ADCX Rob posted:

Don't bend any tabs.  Remove / service baseplate w/o bending tabs.

Servicing the base plate is not being discussed as riveting a new pickup assembly is not in the skill or tool set. Replacement is what has been settled on and that absolutely requires bending the metal retaining tabs around the axles for installation. I don't see any need to unnecessarily introduce potential to malform the bolsters positioning (however small) when the old base plate is likely to be discarded, but I did disclose the method (along with riveting and such) in the prior posts.

Yes, bending just once for a new part.  But don't do any un-bending for removal or service, it's unnecessary and will break the part.  The bolsters don't "malform", anybody with good service experience can remove & replace wheels/axles 50x easily w/o affecting the shape, spring rate, or staking of a postwar truck.