Athearn Ready to roll RS-3 94070 power trucks

[einotuominen]

Hi,

This is my first post on the forum

I have an Atheran RS-3 catalogue number: 94070 which needs a new front power truck. I found the parts diagram online and it says that the front power truck is part number 46009. However I can not find this part anywhere online.

Do any of you guys know where I could buy this part and with international shipping (to Finland). Or if it is not available, do any of the other Athearn power trucks fit in to my loco?

Best regards,
Eino

[nsc39d8]

Found these but you have to buy the pair:

RS3 power trucks

[lvrr325]

Here's the dirty secret on these. The Athearn RS3 is the old MDC Roundhouse RS3. As originally designed the drive was mostly blue box Athearn components, there are a couple of variations of it. MDC before Horizon bought them, to try to improve the drive, bought Proto 2000 parts and used them in it for the last run or two. The Proto drive was cloned from the Athearn drive so it was a direct swap.

When it became an Athearn product under Horizon, it continued to use the exact same drive. I had a couple and I about fell over when I looked under them. I had to change the gears in them, is why I noticed. While the Proto is a close clone, there are some minor differences and all were apparent on the engines I had.

So that means you can use any pre-helical gear Proto 4-axle truck under it, it should fit fine. For that matter an Athearn truck should also work, but if it uses the contact tab, Proto are on the opposite side from Athearn. However the Proto sideframes may not fit 100% on an Athearn truck (one of those minor differences I mentioned).

In fact, if you're replacing the truck because it's locked up or jams, it may just be the axle gears have split and you can replace those instead.

[einotuominen]

Thanks guys!

Nov 22, 2023 8:34:21 GMT -8 nsc39d8 said:

Found these but you have to buy the pair:

RS3 power trucks

These are the exact parts. The price is quite heavy though.

Nov 22, 2023 9:03:07 GMT -8 lvrr325 said:

Here's the dirty secret on these. The Athearn RS3 is the old MDC Roundhouse RS3. As originally designed the drive was mostly blue box Athearn components, there are a couple of variations of it. MDC before Horizon bought them, to try to improve the drive, bought Proto 2000 parts and used them in it for the last run or two. The Proto drive was cloned from the Athearn drive so it was a direct swap.

When it became an Athearn product under Horizon, it continued to use the exact same drive. I had a couple and I about fell over when I looked under them. I had to change the gears in them, is why I noticed. While the Proto is a close clone, there are some minor differences and all were apparent on the engines I had.

So that means you can use any pre-helical gear Proto 4-axle truck under it, it should fit fine. For that matter an Athearn truck should also work, but if it uses the contact tab, Proto are on the opposite side from Athearn. However the Proto sideframes may not fit 100% on an Athearn truck (one of those minor differences I mentioned).

In fact, if you're replacing the truck because it's locked up or jams, it may just be the axle gears have split and you can replace those instead.

Well I actually took a closer look just some moments ago and tried to fit in Athearn bluebox truck and it seems to be of correct measures in every way. The components are are exactly the same for most parts of the truck.

So I think this solves the issue.

So for a little background... I'm running Märklin three rail system. However I wan't to run US stuff on it and as Märklin's loco range is quite limited, I have started to convert two rail locos to three rail and adding Loksound decoders. The Athearn trucks that can be found in Proto2000 locos also are the easiest to work with. Basically a pickup shoe or slider needs to be installed under the bogie, but it needs some vertical clearance, so some surgery is required on the truck. I've made several of these successfully, but with my RS-3, I had a misshap and cut the truck in a wrong way.

Anyway it seems that the bluebox truck will be a 100 % fit.

Best regards and greeting from Finland,
Eino

[lvrr325]

I will say just for anyone else who reads this down the road, around 1995-ish I put a Proto 2000 drive out of a BL2 into a blue box GP38 and it went right in - but it ran backwards from everything else. For whatever reason the frames on BB GP38-40-50-60 are designed to only accept the trucks one way, and Proto put the tab on the opposite side. With DCC this is irrelevant, you can isolate the motor and fix that. You just need to be aware when combining parts to make sure you don't create a short circuit.

Any reason you can't make a shoe that just snaps on these trucks in place of the lower gear cover, or mounts to it in some way that doesn't interfere with the gears inside?

[einotuominen]

Nov 22, 2023 22:13:36 GMT -8 lvrr325 said:

Any reason you can't make a shoe that just snaps on these trucks in place of the lower gear cover, or mounts to it in some way that doesn't interfere with the gears inside?

Hi,

Actually there is. The Märklin pickup show requires around 2-3 millimeter more clearance than there is with the gear cover or even without it. On a straight track it might work, but when coming to a turnout the Märklin center rail studs form an incline so the pickup shoe is lifted up towards the bottom of the loco. The studs must raise and the pickup shoe with them because otherwise it will hit the blade of the turnout and short circuit.

If there is not enough room for the pickup shoe to move vertically, the studs will lift the entire loco up and then it will derail as wheels are also lifter from the rails.

I have photos on my Google Drive as the forum seems to have exceeded attachment limit.
drive.google.com/drive/folders/1FtWLCG0xcSOE1C73xIg9c5Kasb8N56Gi?usp=sharing

BR,
Eino