# Question to Greg E on PA's & SD40-2 blocks.



## noelw (Jan 2, 2008)

I seen your web site (_ pasted below _) on how to make the PA's and SD40-2 track better and as I was lubing the swivel and then I fig. I would go and lube the motor block gears. I was reading that the bushing have to have no point up on the F , GP9. GP 30 & GP38-3. They have to have them laying flat ( Sq. top on bushings.) 

Is there a reason for this that the PA's & SD40-2 are difference that the others that USA make? 


_ Here is the part that was on your PA repair links.. _

*Disassembling the trucks:
To remove the cover that goes over the main gearbox, remove 6 screws and lift the cover off.
Notice how the brass bearings are aligned. They fit in a slot in the housing. It's easy to not get
them in place. The brass bearings need to have one of the points pointing straight up. This is
VERY important. Many people destroy these after taking them apart, and not getting the
bearings back right will not allow the gear mesh to be right, and you WILL destroy the gears.* 



Is it because the difference gears with an idler in it to make it seat better? Maybe difference size gears?

I know others have had this problem to on messed up gears.... due to just hitting on the tops of them when putting on the cover and not ck'ing the bushings. 

I went back to some of my USA two axle block and they have to have the bushing flat or it will mess up the gears in time. 


Anyway, I keep getting questions on this from guys and USA can't seem to give us an ans. on why the bushing seat difference on difference blocks with the same kind of bushing.
This might be something to watch for when lubing up USA blocks.


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## Greg Elmassian (Jan 3, 2008)

All I can figure is that they used the same bushings, and whoever designed the blocks came up with the different orientation. 

It is a very dumb idea, since you have to remember the different orientation for the 2 axle vs. the 3 axle. 

At first, I did not believe it, but I carefully disassembled several locos and proved it to myself. 

Fail to reassemble properly and you damage the gears. 

2 axle flat, 3 axle point up. 

Regards, Greg


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## noelw (Jan 2, 2008)

Ya.. Greg.. I did the same thing by taking the blocks apart like you did and checking on what was going on.. Just wonder if you hear something on it from USA or others. 
Guess its a good note to keep in the back pages for others here.. tks guy..


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## Greg Elmassian (Jan 3, 2008)

Yeah, it's pretty darn often I get contacted by people with "stripped gears" and when I ask if they messed with the motor blocks, they say "no, I just opened them up to look inside".... bam! the axles shift, and the gears get out of mesh, or too close in mesh and you have plastic shavings instead of gear teeth. 

Pretty darn weird to do the same bushings differently on different locos... I've rarely met anyone who knew they were differently oriented. 

I don't expect anything from USAT, since they have never really fixed the split axle problem. I can't give them a hard time though, look at all the split Bachmann connie gears, or all the Aristo power trucks that don't pick up power from all wheels. 

Just something to learn and remember... part of the fun of the hobby, learning the "tricks"... 

Regards, Greg


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