Kato GS-4 issues

Hello:

I was lucky enough to acquire one of the Kato GS-4's when they first came out. Since it was a first run, I had to install the retrofit kit to install DCC. Unfortunately, afterwards the decoder didn't respond. Evidently, the retrofit wasn't applied right, although I could never figure out why. And eventually, after replacing the original board, the engine started acting very balky--wouldn't run if power was applied, or would do so very inconsistently. So I put it away for several years.

Fast foward to now, and I figured I'd give it another look. I started by taking out the retrofit inserts, with plans to reinstall them later (but hopefully right this time.) Then I tested the engine. Still the same issues--on standard DC power, it either won't move, will do so with a large amount of jerking, or will run perfectly fine until it stops. I've ruled out dirty wheels as the problem--I cleaned them several times, and if the drivers are suspended in the air while power is applied to the tender, the drivers spin perfectly fine. I have had to fiddle with the drivers--all four sets popped out while trying to remove the inserts, and although I think I replaced them correctly, it's possible I didn't. I'm not totally sure what's going on here--could someone give some advice?

Also on the inserts, I currently only have the two that I placed on the engine way back--not sure where the others are. Does anyone know if more are available somewhere, or could be crafted?

 

There are only 2 plastic inserts for the Dcc fix, but the kapton tape is far better. And if you had the drivers apart did you notice if the collars or axle tubes are cracked? This happens and the have a new axle set for them from Kato USA but be patient as taking those pins out of the side rods isn't bad getting them back in is a little tricky. Now the new locos have been released and you can find them on feebay for about 170$ shipped, and they are truly Dcc ready and with the new axles.

 

the engine not running right sounds more of a symptom of the contact from the L shaped contacts to the upper drawbar making contact. This is a complicated method of getting power to the motor and if everything isn't pressed in just right, everything from no operation to jerky operation takes place.

There are only two spacers. This is only necessary on 126-0301. Half came with the spacers pre-installed, half needed the retrofit.

Make sure the bearings are correctly reinstalled...they fit in slots in the frame and are held on with the cover plate.

On the drivers, make sure there aren't cracked axles. The drivers were redesigned a couple of years ago but it takes a bit of patience and know how to install them.

Enjoy!

Kelley.
www.dufordmodelworks.com

 

Get ride of the shims-remove motor and isolate . Use two wires for the motor and run to the tender and hook up to the decoder. Using the shims is like using a band aid for broken leg!

 

As I recall, the power pickup from the drivers were done via a star washer type setup and the washer sometimes would stop touching the driver leading to bad electrical conduit as well.

 

Thanks for the replies. I'll take another look at the axles, and I may just get the updated driver kit. I'll also try the kapton tape fix. As a college student, I don't really feel like dropping $170 on another GS-4 yet.

While I could be wrong, I don't think it's a problem getting power to the motor. As I stated, the engine and drivers run perfectly fine--if the drivers aren't touching the track (or anything else). On the rails, it's anyone's guess how well it'll run.

 

I have one of the black Executive GS-4s coming and will compare it to the three older ones I have. All of them still run great but because of the reported issues with drivers I have ordered driver sets for my older engines so I am ready in case they fail. Better to do it now while they have the parts, may not have them in a year.

 

Don't bother with th Kapton tape! Fix it right the first time-this locomotive has cost me more decoders than all of the rest of my installs 'over 1000] The problem is that when the drivers hit the frame it is a motor to rail short>there goes the decoder! I will not install a decoder unless I can insulate the motor 100 % I don' care which run it was I have been burned too many times with this loco.

 

SVR,

I too have one of the very first production runs some 10-12 years ago. I'm 76 and can't remember exactly how long ago they were released but that isn't really important. What I can say is that most all of the comments/suggestions offered so far are right on. However, I can tell you from first hand experience and from findings of Mr. Max Magliaro, who installed the "new driver set for me, approx 3 years ago. He found and I can confirm that the GS-4 bearings will not stay in the grooves on the frame. These frame grooves are cast pieces and the casting is or was terrible. The bearings would not stay in place and that caused the loco to hop, skip, jump, and fart and fall by the wayside. After Max returned my loco it ran fine for about 3 hours and bingo, not worth a plugged nickel. I took the bottom cover off of the bottom and exposed the drivers. What I found is absolutely unbelievable. One of the bearing blocks had popped out off its groove and traveled all the way across the axle and was free wheeling against the other side. What a deal and I swore no more KATO steamers. Then came the FEF and changed my mind so I gave in and purchased one of the new GS-4's. I called KATO USA and was told that nothing in the chassis would be changed but they would use the "new" driver set in the new GS-4.

I have rattled on enough, but I can tell you that before I ever attempt to run my new loco, I will check the bearing blocks to see if they are still loosey goosey. If they are, I will use Mr. Magliaro's fix.

Always have fun,

Carl

 

What is it about about the plastic inserts or the Kapton tape fix that makes it insufficient to keep a decoder from being damaged? Are there other causes of a short circuit on the first run GS-4 besides the backs of the drivers touching the frame?

Are models after the first run sufficiently isolated to make a decoder install safe? On the subsequent runs, did Kato apply some kind of insulation to the frame to keep the drivers from shorting to it, or did they actually isolate the motor from the frame?

I will soon install a decoder into the latest run, so if there is still a problem I would like to know. Has anyone had a problem with blown decoders on models after the first release?

Jim

 

I just got the latest run of the GS-4 (126-0307) and was disappointed to find that it almost immediately showed the loose driver bearing problem. It started with a clicking noise and a bind at low speed that got bad enough to stop the engine a few times. Either the new driver design does not always fix the problem or they really didn't use them on this model as claimed. For those who do not know of this issue, see post #6 in this thread:

https://www.therailwire.net/forum/index.php?topic=35367.0

I took Max's idea and used a section of coffee stirrer, the plastic kind with the hollow center. Cut a slit lengthwise and pop it over the axle of drivers 2 and 4. My stirrer was a little wide for the axle slot, so I shaved off a little bit on one side of the of the slit until it fit. It's pretty easy to do, just don't take the drive rods off of the wheels and the dexterity required stays low. I've been test running for 45 minutes so far and no problems, although rougher track work on another layout may still trigger the problem if I haven't made the piece of stirrer long enough.

It's really a shame that the GS-4 has this problem. It really is an unforced error as the Mikado and the FEF bearings are better designed. Otherwise it is a nice design.

Jim

 

Jim,


Thanks for the input. I have talked to several people about this loose bearing issue and have never found anyone willing to say they have the same problem. Perhaps they didn't want to admit it for some reason. As I mentioned in my original post Max Magliaro did the very "fix" to the #4 driver on my GS-4. But the #2 needs the same fix.

I am a little bummed to hear that your "new release" loco has the problem. I too have a new one but have not run it at all. I really like your stirrer fix and will try that.

Thanks again for the suggestion, and always have fun,
Carl

 

The later run units (126-0302 and forward) have modified upper frame halves with recesses so the drivers can't short between the upper and lower frames.

 

I went ahead and popped off the bottom cover plate of the engine. As far as I can tell, there are no cracks in the axles or tubes. All the bearings seem fixed where they are.

IMG_1286 by SVRailroader posted Apr 15, 2017 at 12:27 PM

I tried applying power--still with the plate off--to see the drivers. They spun with no apparent issues, although driver #2 seemed to be a bit higher (when engine is upright) than the rest.

Then I tried placing a piece of Atlas Snap-Track on the drivers. And all of a sudden, with little pressure applied, the drivers slowed way down and #2 started bucking up and down. The bearings did not move along the axle or rotate, but bobbed up and down with the wheels. I have video, but I haven't figured out how to add it to the posts yet.

I'll give the coffee stirrer trick a try and see what happens. Then I'll go for the new drivers if that doesn't work.

 

Gotcha. Here's the first video, with the drivers freewheeling.

Here's the second, with a piece of track placed against the drivers. Watch #2.


I can confirm that these are the older drivers. It's a first run engine, purchased new, and I haven't swapped them out yet. Also, I think the rear pair looks out of line because the rear drivers are sprung, diverting weight to the third (geared) set. So when the engine is upside-down, they naturally pop out a bit. They could be off slightly, though, I'm not sure. Since I can make the engine run sometimes, I don't think it's a huge issue.

 

Wowsers !!! That wheel jumping like that in the last video is something weird for sure...at least to me !!!

 

That "wheel jumping" doesn't surprise me one bit. The video captures an abnormal situation where the other wheels are being forced to slip against a stationary track, under "reverse gravity." What do we expect? From what I understand about this design, I would expect something strange in this type of scenario. These locomotives are designed (by the number one designer of N scale locomotives for.......let's just say forever) to be gently placed on a track and ran under normal circumstances. Many of us have done nothing other than this, and experienced nothing other than the usual high level Kato performance. I've read some of the "horror stories" where people buy these and put them through a torture break-in, only to find that something is no longer working as it should. Not me. I see these locomotives as complex, delicate mechanisms to be treated accordingly. So far, no problems whatsoever....

 

This is what mine did after a some test running. Driver #2 was all over the place. One of the bearing blocks (or both) has likely come out of it's slots. Mine tended to sit 45 degrees off from the proper orientation and a little bit above the pocket where they are supposed to sit. Add a little bit of drag and the blocks start spinning and moving around. It occurs to me now that it is possible that it was assembled that way. It would be very easy for the assembly technician to miss.

Jim