Hard to hear if there is anything going on inside there Dennis. The sputtering could be something else besides the gearbox perhaps, hard to say. I guess we'll see what it all looks like when you open it up.
Ok, I pulled the Polar K4 apart and that intermediate gear is pretty loosey goosey.
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@Dennis Holler ………🤮….you’re no stranger to danger Dennis, catch me via profile, and I’ll send you the dimensions if you want to duplicate my part,…..I know you got a good supply of stock and junk like I do …..
Pat
Wow, that's a lot of play.
@Dave NYC Hudson PRR K4 posted:Wow, that's a lot of play.
I think Dennis has a record holder,……his goes clear across from one side to the other,…..one more mm and I’d bet the intermediate shaft could jam up in the spokes!!!….😬
Pat
Yeah Pat. Out of all the ones that you've shown jumping around, his definitely goes way past the out of bounds line or yikes line.
I’ve had a few dozen of these come across my plate now Dave, and while I’ve had some doozies, I have no idea how Dennis’s could even be running!!…
Pat
Gear Box List Updated on page 1
Heck Pat, I did not realize that Dennis's engine was not on the list. I added the Polar Railroad 6-11331 conventional from 2011 to the list.
ok so is anyone selling the brass stock with set screw?
@prrhorseshoecurve posted:ok so is anyone selling the brass stock with set screw?
Read page 1, first post ….
Pat
@Dave NYC Hudson PRR K4 posted:Gear Box List Updated on page 1
Heck Pat, I did not realize that Dennis's engine was not on the list. I added the Polar Railroad 6-11331 conventional from 2011 to the list.
Thank you Dave!…
Thanks Pat, I'll shoot you an email here in a bit! Like I say, I bought that Polar K4 used so have no idea how much run time the PO put on it. At least all the legacy stuff works fine so this should be an easy fix. Looks like the Bronze idler gear wheel is still in good shape. I'll find out how worn that little bushing in the chassis is I guess when I take it all the way apart. Would be a good time to repaint it in a PRR scheme if it wasn't cold outside lol.
Also just to clarify, it is the Legacy version of the Polar K4 but I was running it in conventional format on my ZW. The box is up in my attic so not sure what the SKU number is at the moment, but I'm sure both the conventional and Legacy versions suffer the same problem.
This thread is a great resource!
Dave, looks like the Legacy SKU is 6-11330 so I guess you can add that one to the list as well. 
@Dennis Holler posted:I'll find out how worn that little bushing in the chassis is I guess when I take it all the way apart. Would be a good time to repaint it in a PRR scheme if it wasn't cold outside lol.
If you shine a light behind the middle driver you can see the bushing with the shaft in it. Moving the loco back and forth a bit with the gearbox locked, i.e with the motor still attached etc will show any obvious wear.
The shaft will do more rocking than rolling. On my 11328 the bushing on the engineers side actually started producing bronze shavings....maybe it was more brass than bronze, thus the wear. My engine had 1 hour of run time tops.
@Dennis Holler posted:Dave, looks like the Legacy SKU is 6-11330 so I guess you can add that one to the list as well.
Okay, I will do that when I get home. It's really tough to edit on the phone. Thank you for that information.
@harmonyards posted:I’ve had a few dozen of these come across my plate now Dave, and while I’ve had some doozies, I have no idea how Dennis’s could even be running!!…
That looks a lot like the chassis I sent you that had failed. It looks like there's some chunks out of the gear teeth on Dennis's K4, he's skating on the edge!
@gunrunnerjohn posted:That looks a lot like the chassis I sent you that had failed. It looks like there's some chunks out of the gear teeth on Dennis's K4, he's skating on the edge!
Correct, ….yours was completely missing the worm John, I did a before & after test ( yours was the original Guinea pig ) so we know the fix can save them,……I’d imagine there are some brutal ones out there that can’t be saved, but so far what’s come across my plate have all been saved,…..I would have no problems putting that chassis you sent me back in service……
Pat
That's great news. My K4 fleet is still boxed and unopened waiting for me to send out, along with Mikados. One project at a time. Haha
Okay, updated once again. 
@harmonyards posted:Correct, ….yours was completely missing the worm John, I did a before & after test ( yours was the original Guinea pig ) so we know the fix can save them,……I’d imagine there are some brutal ones out there that can’t be saved, but so far what’s come across my plate have all been saved,…..I would have no problems putting that chassis you sent me back in service……
Pat
Hmm.
Pat I think I have one in the junk parts box I changed out that came in for repair some time ago. Might have to send you a pic to see if it can be saved to repair when one comes in.
The one you fixed for me ran great over the holidays.
Jim
