Bachmann B23-7 noisy

[Power Stroke]

I picked up one of these on ebay for cheap (15.00) and free shipping, so what the hey, I'd be stupid not to, based on Spookshow's review, and Mark is very rarely wrong.
It looked to be in fantastic condition but as part of an estate purchase by someone who could not verify if it even worked, I was taking a chance.
It showed up in all of it original packaging complete with paperwork, and looking at it, I'd swear it had never been run, or very little at the most.
Well.... Binds in RH curves going forward with unreal gear noise, and noisy in reverse. It has an acceptable noise level going straight, and in LH turns but I have noted a slight slow down but with no gear noise.
I have had this completely disassembled including trucks, and although it was spotless, I cleaned everything with DeOxit, and lubed with WS ultralite oil, checked freeplay front and rear, which seemed good if not excessive, and reassembled but no joy.
I have now spent hours trying to sort this out but to no avail. I isolated the issue to the front truck by finally removing the driveshaft but the motor does not have enough nut to move this thing on just one truck without also using finger assistance.
Any ideas on what I may be missing, and how to accurately adjust the shafts on this unit.
I really like it, and it is pretty much dirt simple but I am missing something.
Thanks,
Stephen.

[Mike C]

This may help......http://trainweb.org/passengercars/Bearingblock.pdf

[Power Stroke]

This may help......http://trainweb.org/passengercars/Bearingblock.pdf

Mike.
Ron's fix only works on Atlas/Kato/Life Like, etc; that use bearing blocks. Ron and I have had personal conversations about said locomotives, and I have used this method with success. However, the Bachmann B23 has no bearing blocks but rather universals and shafts with the worm gears contained on the trucks.
I would appreciate an answer from Bachmann, or someone familiar with this locomotive as there has to be an exacting procedure to set these up.
I am guessing truck to universal should be a specified length, motor universal to motor universal should be a specified length, etc.
I will take pics and repost for those who haven't taken these apart.

[Power Stroke]

Pics of Bachmann B23-7.













As can be seen from the pics, freeplay is adjusted by moving the universals on the worm, and motor shafts. There are no shims for the worms, and the worm is something I've never seen before, in that there is a hex on one end but for what reason I am unsure. The worm is also plastic.
Wouldn't access to a service manual be novel? However, I'm guessing in this day of throw aways, it's just easier to replace, rather than service or repair.
I don't get it, some of my motive power is 40 years old, and when set up and maintained properly, run as smooth, and almost as quietly as new units, albeit, straight cut brass gears are never going to be noiseless.
Anything but total perfection from these modern locos with helical cut plastic gears, and virtually noiseless motors really should be unacceptable, and all of manufacturers are guilty of foisting duds on us modelers, with no access to ways to repair them ourselves. All we get are cute parts diagrams.
But I digress.
Good looker, potentially great runner, boy would I like to get this sorted out.
Thanks,
Stephen.

[James in FL]

I think I would have started right where you did. The position of the universal cups along the shaft.
How tight is the drive shaft when a right turn? What do you see when the shell is off and running?
What is different? When under load, where is the slop? Worm? Drive shaft?,
I suspect something is moving more than it should be, or jamming when a bit too tight.
I don't have this model.

In the third picture...
To my eye, I see a (vertical?) misalignment that's probably partially to blame.
The angle is off.
That masking tape around the motor maybe holding it off.
The motor seems to need to fit lower in the frame.
Could that yellow plastic (motor mount) be 180 off?
Try that, if you need to insulate, a small piece of Kapton tape.
When you had it apart, was there play in the motor shaft front to back?
I dunno, you may have already checked.

Maybe check again for split gears?

I hope you figure it out.
Keep us posted.
Good luck

[skipgear]

The dog bones / drive cups have nothing to do with it. They don't move with the trucks. The only thing that rotates with the truck is the gear that contacts the worm. It looks like pretty fine pitch from the parts listing. My guess is the mesh doesn't have enough play to allow for the misalignment when the truck rotates.  In the direction of bind, the worm is pinching the worm gear.

An easy solution, something that I found worked on the early Atlas VO-1000's that nobody liked was to bend up the pickup tabs slightly to help lift the frame off the truck a bit. This loosened up the mesh and made the loco 100% quieter. It may work in this situation.

IF it needs more than that, take a small file and remove some of the material where the truck clips in to allow it to fall a little farther away from the worm.