LL SW9 noise

[csx2749]

I have several LL SW9's and some run pretty quiet and others grind away. Anyone have any experience improving their performance?

[alco539]

Good morning csx2749. I have the same problem. I have two, one is "somewhat" quiet, the other is very noisy. They are worse on curves, miss-alignment somewhere.

I've had them both apart several times to solve the problem, but to no avail. My gut tells me that the trucks (rear the most) have too much back and forth movement. The one that is really noisy is quieter in reverse than forward. On my most noisy unit the diecast frame appears to be poorly cast too, making the motor a poor fit. The little flywheel (IMHO, useless) is close to rubbing on the frame. The metal is brittle so can't stand much bending. It's also very thin in the flywheel area, it can't be filed much for clearance. Bending it out also makes the truck pivot area even looser, making the unit noisier? The pick ups come into play also. Too much "spring" or "not enough" changes the the contact between the worm and worm gear on the truck, and effects pick-up.

Beats ME, and I've been tinkering with N scale loco's since the early days. Sometimes, "the dog just won't hunt" and you have to take what comes or sell it off! Sorry no "easy fix".

If someone knows the "easy fix" let us know. Regards Charley.

[eja]

Place the noisy unit in a blender. Turn on HI for a few seconds and then turn it off.

It will be very noisy while the blender is on. However, once returned to the OFF position both the blender and the LL switcher will be very quiet.


Works every time.

[douggosha]

I like the noise they make (mine are all from the first run). It sounds like they are really working to move those cars.

\:^)

Doug

[bnsf971]

The issue seems to be the little brass tabs that conduct power from the trucks theough the plastic body to the frame. Some are bent downward more, and that seems to be the source of the noise. The tabs hold the body up and the worm further away from the gears in the trucks.

[alco539]

Terry, as Joe Don Baker (actor) use to say in one of his roles "you done good", that was it. The contacts on the trucks were bent down. A little bend up, mostly on the rear truck (the front is almost level), changed the mesh between the worm and worm gear on the truck. Both of my units run very quiet now. I played, as I said, with spring contacts, but needed to get the truck contacts under my Maga-visor to see they were bent down. Thank you for the fix!

As an aside, I have two sets of MT FT's, both B units were very noisy. I found two problems.

First, the insulting material (tape) forces the motor carriage, and thus the motor and flywheels down in the frame. The A's I have didn't have the "same tape job" on them and were quieter, more in a moment. I removed the tape where the carriage fits on top side of each frame half (not where the motor is, SHORT!), which allows the carriage/motor to move up into the frame notches/slots. I shimmed it with sheet rubber on the underside to hold it in place, but not too tight!

The worm drive shaft alignment is straight now also. By the way the MT FT's already have the "Ron Bearden" treatment from the factory, no inner bearing blocks. see Spookshow site, Atlas GP40.

Second, the trucks on both A and B units had a lot of back and fourth movement. I put a drop of ACC on the inner side of the frame circular pivot points for each truck, let it set, then added another drop, let it set. This keeps the truck gear case from moving back into the flywheel. I don't know how long it will last, but should last a while. Shim stock could be glued there, but I was testing a theory. I wanted something fast, and it works.

The combination of the lower motor/flywheel position and the trucks moving back into the flywheel, causes the noise. I thought that was the cause of the LL SW9 noise too. Like EMD's old saying, "Every Model Different", so you can't apply the same fix to all, lesson learned!

Also, I'm sure not "all" MT FT's are noisy, just like the LL SW's, luck of the draw as they say. My FT B's were mainly noisy in reverse when pushing a "load", which pulls the front truck into the flywheel. In a ABBA lash-up, usualy the trailing units "growled". I guess once you "wear off" the tips of the worm gears on the trucks they'll quiet down with no "mods", LOL.

Regards Charley.

[secretweapon]

I replaced the plastic worm gear with a brass one from Kato. IIRC it was a C-44 part. Then used jeweller's rouge & no problems in like 10 years. Plus they move at around 3 ties a min. if you like to go slow.

[alco539]

I thought about "lapping in" the gear fit with something like jeweller's rouge. However, even if throughly cleaned off after "run-in". I was afraid that in would "embed" in the plastic and continue to ware the gears out, mainly the brass worm. Since you changed the worm that wasn't a problem, I guess. Ten years is prove that no harm was done, thanks for the tip.
Charley.