USAT S4 motor truck squeak

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DVS4G

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Hello all. I'm working on an S4 loco that, of course, has the R22-12 motor truck. The thing was run a bunch during the Christmas season (It's the Santa Express) and now seems to have developed a pretty good squeak as it runs. Total teardown of the motor truck shows no wear on the worm or axle gear. The grease in the journals was pretty solid. The grease in the gears was pretty sticky. So, cleaned it all out. Washed with a little dish soap. (not the motor...ha!) Re-lubed with some nice Moly grease. Screwed it all back together with attention to the worm gear lash screws being (what I hope is) just right. Applied some power and the dang thing still squeaks just sitting in my hand running. Now, those of you with experience know that this motor truck does not have the brass bearings like an R22-115 you find in a GP7/9 or 38. To that end the axle play in this S4 truck seems a little sloppy compared to the other with the bearing. Anybody agree? Or, am I just wrong? It seems the axle is supported simply in the plastic hole through the case and by the square extrusion on the bottom cover that fits under the axle. I did kiss these surfaces with a bit of moly lube. But, as I said, still squeaks. This brings up questions. Is there a better lube for this metal axle to plastic "bearing"? I have some PTFE powder I though about trying. But, I thought I'd see if there were any learned opinions out there before I started experimenting.

Any ideas? Thanks for listening!
 

Greg Elmassian

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Nope, you have the right grease, in my opinion. The moly will work into the plastic and stick well to the metal axle, superior to teflon powder that sticks to nothing.

is the axle play side to side or rotational "runout"?

Greg
 

dunnyrail

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Hm does it have any plunger pick ups, these are known for causing an irritating squeak. Solution is to apply some LGB 50010 Smoke Fluid to the rear of the flanges. Must be the LGB stuff though as it is a lubricant/cleaner as well.
 

PhilP

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No plungers, to my knowledge, on the USA Trains blocks..
<Edit> I actually mean the carbon-brushes, as in the LGB blocks, which contact the rear face of the wheels - see below. <End >.

What state are the traction tyres in? - You don't have a piece of traction tyre trapped anywhere, perhaps?
Doubtful, if you have done a full strip-down.

PhilP.
 
Last edited:

ARIA31

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Did you dismantle the complete truck ?
Did you remove the 2 side frames ? Or did you just opened the undercover between the 4 wheels while the truck stayed in the loco body?
If you electrically feed the loco via one set of skates (on one truck) the 8 wheels are running ?
 

LVT

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Could be the motor (armature shaft bearings).
 

Greg Elmassian

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Waiting on answer to excessive axle play. If too much, will change mesh of gears.

1. he was inside, note he talked about grease on gears
2. he must have removed the axles in order to observe that the axle bearings are integral with the housing
3. usat never used brushes on wheel backs on locos
4. NW2 never had traction tires


Greg
 

dunnyrail

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:blush:
My bad...
I was thinking of the carbon brushes, on the wheel-backs.. - Which I had assumed Jon was referring to, with the spot of smoke-oil lube..

PhilP
Yup indeed that is what I was refering to, them in the picture are skates.
 

Greg Elmassian

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Actually for carbon brushes on the backs of wheels, there is something better than smoke fluid, lighter in weight, called "Conducta-lube" made by several manufacturers. Some smoke fluids are sort of slow evaporating solvents, but some are outright oil, not good for carbon brushes.

Conducta-lube is designed to help clean AND lubricate carbon brushes, better stuff.


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