The Athearn Hustler and RDC’s were possibly made that late, but the Geeps and F-units had their drives replaced with geared units many years before then, probably in the mid to late sixties. There were several different versions of geared drives that led up to the ones seen in Athearn Blue-Box and Life Like Proto locos today. Sadly, the RDC molds were damaged and subsequently scrapped a few years ago, but I’m not sure if the Hustler tooling is still around or not.
Bill in FtL
Old thread, but useful thread! 
I found this when looking for info on a replacement rubber band for a Lionel HO Gang Car, and ordered a set of the rings from the eBay seller in MD.
I think I am missing something else on my gang car, but I’m possibly a step closer with the small investment for the bag of drive bands.
The RDC’s and little hustler were made clear up into the 80’s (which was about when this thread started [:D] ) I remember having a lil hustler and putting it on the club layout that was powered by CTC-16 which had a constant voltage. Thing took off like a scalded cat chased by a rotweiler with rabies and an assault rifle. hit a 36" curve skipped the track and skidded three feet across a lake in the scenery much to the amusement of everyone involved. Tough little bugger- didn’t hurt it a bit. (No scenery was harmed in the creation of this picture- it was not long before we were dismantleing that layout) Jim
Maybe it’s been mentioned here already but those Goody brand vinyl hair bands at Walmart have been mentioned as replacement bands for the old Athearn band drives. Having said that I converted an old Athearn band drive RDC to a motorized one with a simple centrally mounted motor and used it on my old layout.
Cedarwoodron
Here we are in 2019 and this thread still seems to be the de facto online info source for the Athearn Hi-F rubber band drive! I’d never heard of the system before a few weeks ago, when I stumbled upon a yellow box Athearn ATSF F7A in the gift shop of my local railroad museum (Winter Garden, Florida, run by the CFRHS, of which I’m a member) and noticed the curiously fat axles. I removed the shell and deduced from the broken rubber bits that it was a belt drive, even though my brain refused to believe it! It was such a novel and different drivetrain that I had to have it. I ended up grabbing the F7A and the matching Globe dummy F7B for the sum of $25. The motor in the Athearn runs well, but I suppose I need to head down to the local Walmart and grab a bag of those clear Goody silicone(?) hair bands and get her going again! 
I noticed earlier in this thread, someone had posted a few photos showing the internal variants of the Hi-F drive. I’m wondering just how old my diesel is…it has the one wire per truck setup, fully enclosed shaft bushings, and black rubber driveshaft couplers. I may add some photos later, if I can manage to attach them.
An Athearn Hi-F drive original in a F7A. The B’s used the same chassis. You can disregard the note. I have 4 of them from 1959…still run…ATSF/PRR:
Athearn BB rtr SDP40 without fly wheels circa 1963. Shell has since be redone and given to a friend of mine in the UK. It also still runs with a new drive line. I had sent Him quite a few engines that I do not use anymore, after I redid them. They also came with cast metal trucks:
Take Care! [:D]
Frank
The Athearn Hi-Fs are tough little machines. I have an ATSF F7A that’s part of a near complete set I bought at a yard sale for $5. It was in pretty rough shape when I got it and not operable, but I cleaned up the motor and wheels, put new bands on it, and it runs great now. I’m not sure of the exact age of it, but I traced it back to around 1957. I also have a Union Pacific F7 A/B set, both powered, that I paid about $25 for the pair, and all I had to do to them was put new bands on and oil them and they were good to go. I’m not sure, but I think they date to the early 1960s.
So I got the Goody clear silicone hair bands from Walmart and installed them in my F7A, but it seems they must be too tight, as the motor struggles to turn and the driveshafts actually work their way free of the motor shafts in short order. I’m disappointed in this result but I assume there must be a better fitting band, and a way to better secure the shafts to the motor?
Best thing to do with those rubber band drives is to put them where they belong in a museum.[;)]
I would agree with Larry. I have 2 of them, both RDC’s, and never planned on restoring the drive.
If your serious about it, maybe get all of the original parts and bands and see if that helps.
There are over 400 Athearn F7’s on Ebay right now, many different price ranges, and even a few old drives and frames.
Good luck!
Mike.
The rubber tubes on the motor must be on very, very tight and the bands on the band shaft, must all face the same direction as in the photo that I posted. You can use neoprene tubing of the same kind that are used in fish tank oxygen lines. They come in different inside diameters. The motor shaft diameter is larger than the band drive diameter so get a size that is very tight on the band shaft and equally hard to get on the motor shaft. I never used what people say works for the rubber bands like what You used, so I can’t comment, but tend to agree that they are too tight. I was fortunate to be able to use exact replacements for them, but they are Not rubber. They are synthetic rubber which does not dry out, but I don’t think you can get them anymore…
Good Luck! [:D]
Frank
There are some rubber bands, ATH 90101, on Ebay. Athearn sold them with 24 in a package.
Ebay sellers sell them in 3 packs? Typical, I guess.
Mike.
I have never tried those hair bands but sounds like they are too heavy or too small the shaft for the bands on the ones I have are the same size as the motor shaft they have a added piece on them The best is the ones with the ball and socket So if you are determined to get them to run replace that small piece of tubeing its probably dried out and no good The bands can still be ordered on evil bay I went looking at my collection and have all the different ones and the three aba set with the kentron update those actually run with geared engines Also found three envelopes with orig athearn drive belts opened one and hard to believe still good But like others have said put em in retirement and the price on them 25 cents
Never dealt with this shop before, but they have an original package, an address and a phone number, might be worth checking out. From a Google search for ATH 90101.
https://www.chuckstrains.com/90101-HO-Drive-Belt-Rubber-Band-24-ATH-90101.htm
There are some out, just have to look.
Mike.
You should try the black Goody “Ouchless” elastic bands. I used them on my F7s and I’ve never had any problems with them. I bought a 250 count value pack, (not that I needed that many, but it was the only one available) and it has three or four different sizes in the pack. I used the biggest size, which, when laying on a flat surface by itself is roughly the diameter of a penny. Also, being elastic, they have enough play in them that the motor can turn the driveshafts and axles without straining. I hope this helps. Good luck!
man my F7 is noisey and shoots out sparks when running around my loop of track i use to test locos on, 'bout as loud as my life-like F7 actually
Are the sparks coming from the wheels (dirty wheels or out of gauge probably) or from the motor?
He’s already started one thread on this, scroll down in the Gen. Conversations.
He hasn’t added any more info, or at least a picture on his problem.
In the first thread, I gave him links to the HOSeeker site, to look up his locos, to help determine his problem.
Must looking for a magical solution, as he gives us no help.
Mike.
those bands from Goodies are what i use for my hustler switcher, and they are a bit small, but i think it’s a good thing, in my opinion, because it grips the drive shaft better, so more traction for it.
yes, the sparks are from the wheels, but it’s because the engine’s shorting out