Large Scale Central

USA SD40 question

Prototypes
#1

Hola Amigos!

My fairly new (< 2 mos. old) SD40 squeaks something fierce! The noise seems to be coming from the rear trucks. Here’s what I’ve done:

  1. Bit of LGB oil on all axles before initial operation. One of the front traction tyres was broken on delivery, so I pulled the other front tyre.

  2. Once the squeals got all the dogs on the block barking, I lubed the axles again and pulled the rear truck’s traction tyres.

The wheels look clean, and the loco operates perfectly. Living in Australia, I’m not keen to wear postage back to the USA for a warranty repair on something that works, albeit noisily.

Short of setting up a mousetrap next to the wheels, I’m out of eye deers. Any suggestions?

Dave

#2

Dave,

One source might be something like this -

USA NW2 side truck frames have a wire eyeleted pigtail on the inside to carry power from the front axle to the rear axle of the same truck. I have an battery powered NW2 that squealed like crazy. Pull the side frame and you may find a wear spot on one of these little wire pigtails. Seeing where it is rubbing, you’ll probably figure out how to resolve it. Since mine is battery powered, I just took them out. You may need to do something different.

#3

TY, Ric!

The swivel truck wheels on the RH side, front and back, are definitely rubbing against something. I cleaned each wheel with a swab of mineral turps (they were dirtier than they looked), then put a tiny bit of CRC on every inside flange. While doing so, I noticed a light grey residue that I took to be plastic dust on the outside of both RH swivel truck wheels. I hadn’t noticed that before.

I’ll have a look for errant pigtails tomorrow.

#4

Hello, Ric!

Sure enough, there were small wear marks on the inside of the plastic trucks opposite the swivel axles. On the SD-40, the plastic covering the swivel axles is purely cosmetic, so I got the little diamond file out and started beavering away.

However, as I filed I began to doubt this was the problem. Both front AND rear trucks had scouring, but the squeal was definitely coming from the rear of the loco. Furthermore, the scouring on the trucks was superficial. My layout is indoor and close enough to circular, so I’d assumed the SD40 couldn’t handle 8’ - 10’ curves. Was that assumption valid?

I put the loco on a spare 6’ piece of straight track to see if it still squealed. It did.

I stopped filing and opened both gear covers, the front as a basis for comparison. Everything looked fine. I removed the gears in the rear swivel section, lubricated them generously with LGB grease, and did the same with the worm gear. After reassembly, the loco ran perfectly, totally squeak-free.

Having to grease the gears on a new loco caught me on the short hop, but it appears that’s all there was to it.

The best thing about all this was that I went right through your entire Kaskaskia RR web site. You are in another league to me entirely when it comes to creating a layout, mate. You have made something of real beauty. However, we do have grandsons and very special women in common!

Regards,
Dave

#5

Dave,

Thank you! It keeps me out of the bars. Jan’s interest is a major portion of what keeps me interested.