Large Scale Central

USAT 3-axle rattle

I have a PA-1. I rebuilt the motor blocks with new gears. Everything is lubricated and I’ve confirmed that all of the bearings are seated correctly. Both motor block rattle as the engine moves. It seems to relate to the U-joint for articulating axle. This is my only 3-axle experience, so I don’t know if this is common. Anyone?

I can post a video if it’s not a common issue.

Thanks

Reassembled improperly is still my guess.

The tips on the 2 axles are “up”? Also notice orientation of the idler axles.

I’ve never had occasion to open the 3rd axle or have universal joint failure. What parts did you remove? Also, why did you have to do this in the first place? Perhaps a clue is there.

Post the video if you would please.

Greg

Eric Reuter said:

I have a PA-1. I rebuilt the motor blocks with new gears. Everything is lubricated and I’ve confirmed that all of the bearings are seated correctly. Both motor block rattle as the engine moves. It seems to relate to the U-joint for articulating axle. This is my only 3-axle experience, so I don’t know if this is common. Anyone?

I can post a video if it’s not a common issue.

Thanks

Video please …I’m not as familiar with most on these motor blocks but I will try to help if I can. I have tinkered with a few here and there though.

Greg,

I have to ask. Wwhat is that light colored band on the middle axle in your photo.

Paul, I think it’s a rubber band to keep that axle from popping out of the motor block when the lid is removed. I use this method, too.

-Ted

Paul Burch said:

Greg,

I have to ask. Wwhat is that light colored band on the middle axle in your photo.

Doesn’t matter Paul as it appears to be a 2 axle motor block which the original poster DID NOT ask about. I personally don’t, do not, can’t see the U-joint that the 3 axle blocks have which Greg asked about which isn’t in his picture that I can see?

Eric Reuter said:

I have a PA-1. I rebuilt the motor blocks with new gears. Everything is lubricated and I’ve confirmed that all of the bearings are seated correctly. Both motor block rattle as the engine moves. It seems to relate to the U-joint for articulating axle. This is my only 3-axle experience, so I don’t know if this is common. Anyone?

I can post a video if it’s not a common issue.

Thanks

Eric,

Something to consider:

I noticed the USA Trains slider shoes can vibrate when attempting to slide on the rail head. I noticed this on my SD70s with 3 axle trucks and an F3 with 2 axle trucks.


Notice above where I was able take the picture that captures the shoe lifting away from the railhead with the SD70 going on the track!

-Ted

If you don’t care Rooster why don’t you just be quiet?

But since you cannot be quiet, that picture is from a SD40, and if you knew anything, you would notice the pivot point and the screw for the “floppy axle” to the left.

Also if you knew anything, you would also know that the 2 axle motor blocks do not have an intermediate reduction gearset.

But you don’t know enough to be quiet, and not courteous enough to not comment where you don’t know anything.

Read THIS twice and stuff it.

Greg

" Rooster " said:

Paul Burch said:

Greg,

I have to ask. Wwhat is that light colored band on the middle axle in your photo.

Doesn’t matter Paul as it appears to be a 2 axle motor block which the original poster DID NOT ask about. I personally don’t, do not, can’t see the U-joint that the 3 axle blocks have which Greg asked about which isn’t in his picture that I can see?

Rooster, I think the motor block in the picture is a 3 axle block. The black color side frames bracket at the underside of the left of the two axle portion of the motor block would identify the block in the picture as a 3 axle block. Also, if I recall correctly, the brass axle bushings have the pointed edges facing up in the USAT 3 axle blocks, whereas, the USAT 2 axle blocks have their brass bushings flat across.

-Ted

Greg Elmassian said:

If you don’t care Rooster why don’t you just be quiet?

But since you cannot be quiet, that picture is from a SD40, and if you knew anything, you would notice the pivot point and the screw for the “floppy axle” to the left.

Also if you knew anything, you would also know that the 2 axle motor blocks do not have an intermediate reduction gearset.

But you don’t know enough to be quiet, and not courteous enough to not comment where you don’t know anything.

Read THIS twice and stuff it.

Greg

If you say so Greg …Good luck Eric

Another clue this is a 3 axle motor block is the tips of the axle bushings are up. 2 axle blocks, are “flat” to the bottom cover. Actually all of this explanation is on my now-inaccessable web site that you cannot access. Thank you Rooster and John.

Greg

" Rooster " said:

Paul Burch said:

Greg,

I have to ask. Wwhat is that light colored band on the middle axle in your photo.

Doesn’t matter Paul as it appears to be a 2 axle motor block which the original poster DID NOT ask about. I personally don’t, do not, can’t see the U-joint that the 3 axle blocks have which Greg asked about which isn’t in his picture that I can see?

Are you seriously clueless or do you just like to see yourself in print, brilliance or not? Just trying to build up your post count?

Shut.

Up.

I think I’ll log back out. Had enough moronity for the month.

TOC

" Rooster " said:

Greg Elmassian said:

If you don’t care Rooster why don’t you just be quiet?

But since you cannot be quiet, that picture is from a SD40, and if you knew anything, you would notice the pivot point and the screw for the “floppy axle” to the left.

Also if you knew anything, you would also know that the 2 axle motor blocks do not have an intermediate reduction gearset.

But you don’t know enough to be quiet, and not courteous enough to not comment where you don’t know anything.

Read THIS twice and stuff it.

Greg

If you say so Greg …Good luck Eric

Ooops. Didn’t get logged out fast enough.

That another “post count” issue there?

Helpful?

Who cares, right?
TOC

Curmudgeon mcneely said:

" Rooster " said:

Paul Burch said:

Greg,

I have to ask. Wwhat is that light colored band on the middle axle in your photo.

Doesn’t matter Paul as it appears to be a 2 axle motor block which the original poster DID NOT ask about. I personally don’t, do not, can’t see the U-joint that the 3 axle blocks have which Greg asked about which isn’t in his picture that I can see?

Are you seriously clueless or do you just like to see yourself in print, brilliance or not? Just trying to build up your post count?

Shut.

Up.

I think I’ll log back out. Had enough moronity for the month.

TOC

VERY CLUELESS …I’m VERY stupid and apologize for overstepping my bounds.

Only posting this to build up my post count …I will SHUT UP NOW AS REQUESTED

Eric Reuter said:

I have a PA-1. I rebuilt the motor blocks with new gears. Everything is lubricated and I’ve confirmed that all of the bearings are seated correctly. Both motor block rattle as the engine moves. It seems to relate to the U-joint for articulating axle. This is my only 3-axle experience, so I don’t know if this is common. Anyone?

I can post a video if it’s not a common issue.

Thanks

Your only post in this thread so far. Have you flipped the engine over, connected power to skates, and actually confirmed that all six axles are turning? Most likely a u-joint slip shaft come apart.

Get the axle bearings right as per Greg’s photo (better than Rooster’s Helpful Photo) or you’ll be buying new gears again.

TOC

After confirmation of the bushings in proper places, I was going to follow TOC’s advice and investigate the drive to the “floppy axle”… and by the way Rooster, you can see the shiny part of the 3rd axle lower left corner of the picture.

(also it’s Ted’s SD40)

Greg

Well, this thread went sideways.

  1. All bushings are installed correctly.

  2. All of the track power stuff was discarded, so it’s not the shoes.

  3. The same issue exists on both motor blocks.

  4. It is definitely related to the articulated axle.

  5. Putting light pressure on the end of the drive shaft reduces the rattle (see video 2), but there is no apparent play in the shaft.

  6. All 6 axles turn and have plenty of torque. The engine runs great. Just noisy.

From TOC:

You can partially disengage the drive to the floppy axle when replacing gears in the main motor block.

Do the bushings in the intermediate shafts look like the ones in Ted’s SD 40? I think they can be displaced too… although not much is making sense in light of you reporting good torque on all wheels.

Do you find you can feel the vibration in any of the wheels? Is it more pronounced in one axle over the others?

Like I said I have not pulled one (the floppy drive) apart, but he mentioned this to me on the phone tonight. It really sounds like the drive is slipping gears.

I think you need to pull it apart and investigate the drive from the “middle” axle to the “lead axle”…

Will ask again, what was the original issue that prompted “replacement” gears? I’m guessing something was damaged, can you tell which gears were damaged?

Greg

Usual split axles. I replaced them with delrin gears that Jerry Yeramian made for me.

I never ran it before replacing the gears, so I don’t know if the issue existed when I bought it. I will try running the B unit, which I haven’t touched to see how it behaves.