Large Scale Central

USA Trains Traction Tires

Modeling Motive Power
#1

I recently converted 2 of my GP38’s from traction to all metal wheels. I purchased the wheel sets from Charles RO. It was a pretty straightforward swap out. As part of the conversion I am left with completely intact traction tires.

The biggest motivation for this is due to general guidance that traction tires can causes the gear’s to crack over time because the wheels are not able to slip as easily. I also at times, would be doing multiple engines when the trains are long.

I tested up-hill pulling strength of my remaining GP38 with traction tires against one with out and as expected its up hill pulling strength is diminished.

Thinking this through though, what would have be the harm in leaving the traction tires in place until the gear cracks, and swapping it out then? The worm gear inside the motor is metal so I can’t see much happening to it.

Thoughts?

#2

Traction tires or not, the gears are prone to crack. I change out the traction tires when they do, but I do it for the conductivity. After that, I just fix the cracked gear with a bit of brass tube.

#3

I don’t change my traction tires out, and the only cracked axles I’ve had, that I know of, came with the used engines I have bought…

#4

The shafts on either side of the USAT gear that hold the axles crack on their own.

Everyone of them, up until the GP30.

The knurling on the axles shafts was wrong and stressed the plastic.

#5

I should have noted that I do battery power so conductivity is of no concern. I think I will leave the one engine as it is until it has issues and then swap em out. If something goes wrong with the others I’ll use up the traction tires too. From what I can tell it mostly damages the axel/gear on the axle.

#6

So up until the corrections were made for the GP30 units, all of the USAT engines had this bad design that resulted in cracked axels? When were the GP30’s manufactured; before or after the GP-9 and F-3A/B units were made? If it was before, then I can expect cracked axels in the future? And the replacement USAT axels are compatible and won’t crack? Sorry if I sound naïve by asking these questions…

#7

GP-9s came well before GP30s and will crack. FA/FB are Aristocraft and a different animal. F3 is USA and can crack.

I’ve found that replacements are no better than originals and will also crack. The brass sleeve is the best way to fix these and avoid any future incidents…, in this respect.

There is an old thread that can be searched that will explain the brass sleeve and the various way that we have found to implement it. People have also wrapped the cracked portion of the gear shaft with fishline and CA’ed (superglued) it in place.

#8

I have a set of brass sleeves that came from Tony years ago. I never used them and all my USA Engines have left the property. They are available at my cost.

#9

Thanks, Todd. I meant USAT F-3/B, not FA/FB, and edited my post accordingly. Thanks for the info on the brass sleeve. I’ve heard about it, but luckily haven’t had to implement it (yet). Surprising that USAT didn’t modify the original design to correct the knurling on the axle shafts like Tony described. Or maybe they did change the part design and it still wasn’t effective?

#10

Jon Radder said:

I have a set of brass sleeves that came from Tony years ago. I never used them and all my USA Engines have left the property. They are available at my cost.

Sorry to hear that. I have a good chunk of change invested in my USA Trains engines and will spend even more shortly to convert them to battery power. Hate to think they’re not very good quality. Funny, a few years ago I was advised to steer way clear of Bachmann engines and to stick with LGB and USA Trains.

#11

I have a USA F3 that won’t pull a train of any length anymore. As Yunz can guess, the wheels spin independent of each other by hand, so the gears are shot. I am going to replace them with wheels without traction tyres, and possibly add a bit of weight to the F3.

Yes, it is my understanding that the axle gears crack, and I haven’t heard of that causing harm to the motor worm. So why not run them till they fail?

#12

I don’t know how much traction loss you experienced, but I had no problems pulling 30 cars up the 4% grade from Mount House to White Rock on TOC’s layout during clean-up without traction tires on a GP9. I replaced the USAT wheel sets with nickel silver ones from NWSL.

#13

Michael Kirrene said:

Jon Radder said:

I have a set of brass sleeves that came from Tony years ago. I never used them and all my USA Engines have left the property. They are available at my cost.

Sorry to hear that. I have a good chunk of change invested in my USA Trains engines and will spend even more shortly to convert them to battery power. Hate to think they’re not very good quality. Funny, a few years ago I was advised to steer way clear of Bachmann engines and to stick with LGB and USA Trains.

Michael - I didn’t get rid of them because I didn’t like them, or they were problematic. I ran them a lot and liked them. They just didn’t fit my overall plan. When I first got started I bought everything I thought was cool. That included a bunch of USA stuff. I settled on Fn3 (3 Foot Narrow Gauge) so I sold off all but one 1:29 loco - my first - a USA New Haven GP9 .

#14

Even though USAT changed the knurling on the metal half axles, the plastic “axle” with the gear still cracks. I have most all the products USAT makes and they have all cracked.

It was my experience that the axles with traction tires cracked sooner, so I replaced all with non-traction tires. The increase in power pickup allowed me to remove the skates.

There was another forum member, now gone, who was trying to get the max pulling power and he was battery and he changed all wheels to traction tires (and used heavy lead acid gel cells. He apparently got killer pulling power.

No reason to remove/replace axles before they crack unless you are like me, if I know it’s going to happen eventually, and often at an inconvenient time, just buy the K&S tubing as specified on my site and do all the axles when you get a new loco, and you will never have to fix it… rather than waiting for them to crack one by one, and open the loco several times.

Since they don’t come gauged properly in the first place, I do pull all the axles out, add the sleeves, gauge them, swap out traction tires and remove skates… do it all at the same time.

Greg

#15

Greg (and/or others) what do you think of replacing the USA Trains GP-9 wheel sets with those from NorthWest Short Line? Is that a good recommendation?

#16

Hmm… first looks like NWSL will only have SS wheels, which are good, but somewhat more slippery. The plating will wear from the USAT wheels, but I believe they are brass inside, a little worn stock wheels will have more traction than SS wheels.

Are you considering this because of a change in profile, or diameter?

Greg

#17

The NWSL wheels have a smaller flange profile than the USAT pizza cutter style. They are a “direct” replacement. However, you have to grind some of the brake shoe material away for the side frames to fit the scale diameter wheels.

Greg, the ones I have where packaged as nickel silver. I wonder of NWSL stopped making them in NS.

#18

Craig Townsend said:

The NWSL wheels have a smaller flange profile than the USAT pizza cutter style. They are a “direct” replacement. However, you have to grind some of the brake shoe material away for the side frames to fit the scale diameter wheels.

Greg, the ones I have where packaged as nickel silver. I wonder of NWSL stopped making them in NS.

http://www.gscaletrainforum.com/index.php?/topic/201-split-usa-axle-gears/

post-10-0-38240500-1394376234.jpg

#19

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Scroll down to “GP-9 Wheel Upgrades”

http://www.girr.org/girr/tips/tips5/gp9_tips.html

#20

Greg Elmassian said:

Hmm… first looks like NWSL will only have SS wheels, which are good, but somewhat more slippery. The plating will wear from the USAT wheels, but I believe they are brass inside, a little worn stock wheels will have more traction than SS wheels.

Are you considering this because of a change in profile, or diameter?

Greg

Scroll down to “GP-9 Wheel Upgrades”

http://www.girr.org/girr/tips/tips5/gp9_tips.html