I found a way to replace split gears on the Arnold Rapido S-2 and other locomotives like the latest production SW1500. A while back, I had dropped a Kato PA and broke both trucks. I ordered new ones from Kato and threw the others into my junk box. I found they are a source for making new gears. You have to cut off the ends but the axle size is the same. The extra tooth does not make much difference. I suppose any of the newer Kato diesel wheel sets use the same part and would work also.
Cool this would have saved me some time and money since the NWSL Wheels/axles/gears I bought wobble. In the end I used the NWSL gears and the stock wheels/axles with the flanges turned down in a motor tool.
I think the LL sw-900 axle gears will work in the same manner. I never brought it up since getting parts for the LL units seems to be a pain. Jason
I'm having a tough time accepting that a 16 tooth gear will fit in place of a 15 tooth gear. My S2 (with SW1200 trucks from Arnold making it an S4) seems to have very little play in the gears. I'm not sure how a larger gear would work in the truck.
I have run the locomotive with four new gears for about 15 minutes and so far it runs quite smooth. No more click-click-click-click from the split gears. Evidently there is just enough slack in the gear train to allow the extra tooth. I just measured the diameter of each gear with my micrometer and they are both about .2 inches. The teeth are just a tiny bit smaller on the Kato gears. Years ago I rebuilt an Arnold S-2 using some Con Cor gears. They were from solid plastic axles so I had to drill out the hole for the Arnold axle. They were a bit wobbly but did not noticeably affect the engine performance either. They were about .195 in diameter.
Russel, just wanted to check in and see how the PA gears are working. Any problems so far? On another note, did the PA wheels have the points on the wheels for electrical pick-up? If so, could you remove the points and use the PA wheels?
BTW, the Kato website says this same geared wheelset is used on mutliple models. I have seen the same number on the U30C, the F units, and the S2 I didn't look any further. I am starting to wonder if the Kato built Atlas RS units may have the same gear, without the pointed wheels. It would be tempting to try one of the traction tired wheelsets in one position to see how it would pull if the gears are the same as the PA (presuming that your results are still favorable).
I can verify this method does indeed work as I have regeared a few of my trucks using this method. I still use the NWSL wheels on my models though. On a totally unrelated note, I was given a S2. It was in parts and had been stripped. The paint stripper attacked the cab and the front is cracked and missing the window posts. Is the hood of the Atlas RS1 the same with as the Arnold S2? I think i'll just cut the cab face off the Arnold cab and put one from an Atlas RS1 in its place.
Thanks Daniel, that is good to know. I have seen so many posts complaining of the NWSL stuff, I think I will take my chances and try the Kato wheels. Hopefully the ones from the old RS3s have the same gears. That would be toooo easy
Still running very nice. Was pulling a bunch of cement hoppers around the test loop the other day after replacing the truck mounted couplers with some body mount MTs using the 1158 Atlas RS-1 conversion kit. Had to do a little fitting but plugged the gaping hole in the pilot quite nicely. The problem with using the stock Kato wheel sets is that they are solid metal and insulated from each other by the plastic gear axle while they ride on the axle points for bearings. The Arnold use a metal axle and plastic centers on their wheels for insulation. The axle, just inside from the wheels on the Arnold serves as the bearing surface. There is no room in the Arnold truck frame to accept the large diameter Kato plastic axles even if you removed the points on the ends. The plastic axle would not make a good bearing surface either.
