AF Legacy SD70 pickup springs

Below are pictures of the process to replace the springs under the axle bearings on an SD70ACe and similar S gauge diesels.

Shown is a truck with the two sideframes removed, two screws each. Next is the truck with the cover plate removed, 10 screws. Then the truck with one wheel set lifted out, the springs are visible in the picture. Last is the wheel set showing one of the bearing blocks.

Thanks so much! That looks like a fairly straightforward procedure. I’m assuming there is only one wheel set that is sprung on each truck (front and rear). I’ll order parts today.

RBG

Hang on. The inner-most wheel set on each truck has traction tires and the bearing blocks do not have springs under them. The other axles do, so 4 springs are required for each truck. There are a total of eight pickup wheels. Picture below of the center axle removed.

Oh thanks! That explains things. It’s a good thing that AM sells springs in sets of eight. I can do both front and rear trucks. I sorta guessed that the center wheels were unsprung due to them being the traction tires. This should be a relatively easy fix. Parts are on the way.

RBG

Oops..I mispoke. The traction wheel sets don’t have springs regardless where they’re situated on the trucks. Without double checking, I just assumed they were in the center. I’ll figure it out. Thanks again.

RBG

I have a ES44SC with pickup problems on Gilbert track.   I ran the engine on fast track and had no problems.   I believe the problem on gilbert track is that some track are not perfectly level or straight. When it stops on the gilbert track I can place my finger on the hood and press down and the engine starts up again......pickup problem...yes.... I purchased some small springs from AM and disassembled the truck assembly today.  Guess what? the ES44 does not have springs in it like the SD70.  No spring at all even though it is the same motor assembly. Can anyone suggest a solution here for my pickup problem. 

I have thought about drilling a hole where the spring would go but I would probably run out of metal before I get it drilled.

Jackie

PS  I have a ES44 N&W blue older engine it runs fine I bet it has spring in it..

I do not have any of the newer ES44AC engines, just a PRR from the first release. That engine works perfect. For the new ES44AC, based on what you say, I would check that all 4 pickup wheels on each truck are in good contact with the chassis. I would use an ohmmeter between each pair of wheels. That is how I confirmed the pickup on my newer SD70ACe's was intermittent.

If the contact between the bearing block and chassis is not perfect one possibility is to add a very, very, very small amount of conductive grease in the pocket. This silver infused grease is nasty stuff and it is unbelievably easy to get a small smear somewhere and have a low resistance short in the truck.

What I have a hard time understanding is why Legacy engines don't include a capacitor amid the massive set of circuitry that they contain. This would fix most of these contact problems.

I remember years (5+) ago having to swap out or reposition traction-tire wheels and solid metal wheels on one Legacy AF diesel or another that I owned in order to create sufficient and balanced electrical contact and continuity with the rails.  It might have been the SD70ACe or U-boats?  Anyway it worked, but as soon as the word got out the part you needed disappeared from Lionel inventory.  As if someone bought them all up.  

Chuck - good point about the caps.  I agree they should be included with Legacy engines.  They're prevalent now on many DCC-Sound HO locos or available separately.  Some of those, however, don't keep everything going when called upon. Some keep the motor and lights going, maybe some sounds, but might drop smoke temporarily.  Maybe the amount of juice needed to keep a fully-featured S engine going for a few seconds becomes space and/or cost prohibitive?  Are there S-gauge Keep Alives, GoPacks, or Current Keepers?  Are they in O gauge?  

Maybe this will help?

http://www.tuveson.com/sd70/im...70_power_pickup_.htm 

Substitute springs that may work?

SPRING COLLECTOR ROLLER / A-F DIESEL

SKU: cs-6408048085-p

SPRING / DRIVER AXLE / .085" DIAM X .200" LNTH

SKU: cs-6308081590-p

SPRING 1/8" DIAM X 1/4" HGHT - 6501105018
SKU:cs-6501105018-p

SPRING / AXLE /.110" DIAM X .340" LTH X .018" THK - 6101104590
SKU:cs-6101104590-p

SPRING / 0.5 Mm X 4.0 Mm X 10 Mm / FIREHOUSE - 6204182425
SKU:cs-6204182425-p

My sd70 has no provision(s) for springs. Removing the wheel sets and cleaning them with a brass brush, I got improved results but the engine would still stall in places. Checked and cleaned the track (Fastrack) for level, etc. and found a couple obvious discrepancies but engine would still lose contact in places. I’m going to try Sgaugian’s suggestion of swapping sides with wheel sets and see if that helps (only about 6 bazillion screws to lose opening things up 😜).

@Sgaugian posted:

Chuck - good point about the caps.  I agree they should be included with Legacy engines.  They're prevalent now on many DCC-Sound HO locos or available separately.  Some of those, however, don't keep everything going when called upon. Some keep the motor and lights going, maybe some sounds, but might drop smoke temporarily.  Maybe the amount of juice needed to keep a fully-featured S engine going for a few seconds becomes space and/or cost prohibitive?  Are there S-gauge Keep Alives, GoPacks, or Current Keepers?  Are they in O gauge?  

Hey Dave.  Most of my DCC installations are a Tsunami2 2200 series which is a 2 amp decoder.  I always add a Soundtraxx CurrentKeeper (a capacitor) which plugs right into the decoder and costs about $25.  The combination of the decoder and the capacitor are far smaller than the space needed for a TMCC installation.  TCS and ESU offer a similar combination and I have installed theirs as well.  If I am including smoke, then I go with TCS WOW501 series which is a 5 amp decoder and which has a capacitor built into the board.  This too is far smaller than a TMCC installation.

Good work Chuck.  Sounds similar to what I prefer to use and install (SndTrx) with HO.  I also own and operate locos with ESU, BLI, Quantum, and other decoders.  

Retired Band Guy - I wish I could find my writeup and the p/n's for better (visually fault-free) L/AF SD70 track continuity through wheel swap or mods, but so far I can't locate it, at least not online.  I might have it in my notes.  But it could all very well be a moot point, b/c as I mentioned, the L/AF wheels or wheel-sets needed for it went out of stock at Lionel nearly immediately after telling others what I did.  Good luck.  Hope you get something to work.  Let us know.  Thanks.

@Sgaugian posted:

Retired Band Guy - I wish I could find my writeup and the p/n's for better (visually fault-free) L/AF SD70 track continuity through wheel swap or mods, but so far I can't locate it, at least not online.  I might have it in my notes.  But it could all very well be a moot point, b/c as I mentioned, the L/AF wheels or wheel-sets needed for it went out of stock at Lionel nearly immediately after telling others what I did.  Good luck.  Hope you get something to work.  Let us know.  Thanks.

It's here: https://ogrforum.ogaugerr.com/...-af-u33c-and-sd70ace

Thanks FlyerRich -- I knew this sounded familiar.  What's odd though is at the time I apparently observed that later release engines didn't have this problem.  Hmmm.  Has it resurfaced?  

The recent SD70's do not have the springs. Got of love the quality from Lionel. Did anyone get after them for this issue? These are still sitting on dealers shelves for sale.

I bought the Canadian National a while back and had no idea. lol  Its a great looking shelf queen for sure.

No, I run it but the problem is just intermittent. Learned to live with it and enjoy.

Well that doesn't sound good.  So they went from with springs and continuity issues, to learning from that and either modified the mechanism and/or electronics to mitigate the problem (still with spring-suspension), to most recently now without springs and back to continuity issues?  

What's the old adage - "what goes around, comes around" (only maybe worse than the first time).   Sorry to hear yours are doorstops or something you have to considerably lower your expectations for in order to operate (notice I didn't say enjoy).  

Dave