Life is strange. If you think about it, most of the other companies out there were building more reliable versions of the Athearn drive system way before Athearn itself decided to. And while Life Like's first P2K offering (the BL2) used alot of parts that looked suspiciously Athearn-like, the materials used and the tolerances that these parts were made to definitely erased any doubts that this was not an Athearn chassis. Same with Kato drives.
With that said, let's talk Genesis...
With the release of the first Athearn Genesis SD75s, it became apparent that Athearn was ready to get serious about its locomotives - drives and all. And, once again, while sharing many similarities with its original chassis designs, out of the box it sounds and operates much like a Kato drive - quiet and smooth. A very impressive step for Athearn, indeed. Many modelers, myself included, only wish that Athearn would build similar chassis for the rest of the Athearn line.
Getting to the Drive.
First off, have the instructions and exploded views handy. Pull the couplers, if they're installed, by unscrewing the coupler box covers. Four clips molded to the bottom of the long hood pass to the inside of the walkway and clip to the frame. Flipping the loco over and looking at the exploded view will reveal where these clips are located. The easiest way to free the shell assembly is to gently squeeze the shell above the clips until they come loose from the frame. Gently pull the shell up, taking care not to damage the bulbs and their associated wiring. I'm not possitive if the decorated units come with the bulbs and couplers pre-installed. I'm assuming that they are, so use caution.
You should now have an exposed Genesis drive in front of you. Take a quick look-see and compare it to the papers. Once again, very similar to a standard Athearn drive but with many improvements. For example, the familiar u-joints and splined shafts are gone in favor of keyed shafts fitting into respective motor/flywheel and gear tower couplings, helping to reduce lots of noise and removing a great deal of play from the drive. A Buhler can motor powers the Genesis line (although I understand that Athearn is now using another brand, possibly a Cannon motor), the same motor that powers thousands of Overland's brass models. Also note the drive shaft angle. While the original Athearn gear towers had the worm mounted horizontally to the truck, the Genesis truck has the gear tower tilted a few degrees up toward the motor, giving the shaft more of a "straight shot" toward the gear tower, thus eliminating the need for any u-joints.
Start disassembly by removing the wire clips that hold all the wiring to the circuit board. Yes, these clips look strangely "P2K-like", and they are. Athearn does include extras in case you lose one or two, and if you lose more than one or two, P2K clips will fit. I also found it helpful to mark what each wire is and where it goes to. I drew a diagram for myself so I could put it back together again. After the wiring is loose, you'll find a pair of clips molded to the motor ends that hold the circuit board in place. Pull the board loose.
The motor is removed by unscrewing the four screws that hold it to the frame, which can be found by flipping the frame over. It sure is easier than the little rubber clips found on the original chassis. Pull the motor from the motor cavity, be prepared to catch the drive shafts.
The trucks are held in place just like the the original Athearn drive. Gently prying these clips loose will free the trucks.
Trucks.
The Genesis 6-axle trucks share some characteristics of the P2K 6-axle trucks. As with the P2K sideframes, DON'T TRY PRYING THE SIDEFRAMES OFF THE TRUCK!! The sideframes will come loose when the bottom cover is removed. The bottom cover is directional - it will only go on one way. The electrical pickup is also similar to P2K's pickup. After the sideframes are free the pickups can be removed fron the truck. Note that the same wire clips used on the circuit board are used to attach the wiring to the pickups.
While disassembling the trucks, this is a great time to mark all the parts so they will go back together the same way that they came apart. Don't forget to note (and mark) where the wiring goes.
The internals of the trucks are represented well in the exploded views in the instruction sheet. I've had the trucks apart to clean out all the excess lube applied to these locos at the factory (see below) and they went back together just fine.
Reassembly.
Very straightforward - follow the above steps in reverse order, reffering to the "explodeds" often, and you'll have no problems.
Some notes:
As mentioned above, For some reason, the Genesis SD75Is that I have came with EXCESSIVE amounts of lubricant. The truck mechanisms look like they had been dipped in lube. Although I'm sure that wasn't the case, the extra lube is overkill. When I first ran these models out of the box, they acted like dirt magnets, picking up any and all dirt, dust, fuzz, grit, loose ballast, etc. in their path. The wheels had a light coating of oil (or grease film - hard to tell), which in turn made the models run horribly with the accumulated layer of crud on the wheels. You'll also find lube on the driveshafts, on the chassis and even up on parts of the shell.
I'm not sure if Athearn was ensuring that the model had enough lube or if it was the "lubricators first day on the job at the Athearn Plant". Whatever the reason, it would be wise to clean as much excess lube and oil from the chassis and drive train as possible. That was the principle reason for my disassembling the chassis and trucks to begin with. After taking it all apart, I soaked and scrubbed all the truck parts, chassis, shell, etc. - everything but the motor, flywheels, bulbs, circuit board and wiring - in isopropyl alcohol and let it dry. I reassembled everthing, this time using only a couple toothpickfuls of Labelle grease and an even finer amount of Labelle oil on the entire drive system. After a test run, I found that the chassis ran just as well, just as silently and with no excess lube for crud to adhere to. Most definitely worth the extra effort.
Now, on the create the PERFECT SD70MACs...
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