Probably been covered before, but here goes: Short of replacing them, is there a simple way to "loosen" up gears in Athearn BB engines? I have some GP35 drives and an F7 drive that seem to be power hungry. In one of the 35 drives, I have discovered that the gears are very tight. (They don't roll well at all.) As usual, any assistance that can be provided would be most welcomed.
Try a good cleaning and lube that should help..
A wild card and the one I chuckle at is using tooth paste on the gears and then running or some such fool thing.
In the 63 years I been using Athearn BB locomotives I never found the need to do that.
I did upgrade all my BB SW1500 and all four CR GP38-2s wheels with Athearn's newer nickel silver wheel sets.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
The gears on the axle should be tight to the axle. It you remove the 'worm' on the top of the truck, you should be able roll it. Removing all the gears and using a fine file to clean up 'flash' may help, but this a very tiring job. If you remove a truck, and remove the worm gear, does the truck roll smooth? It will NOT roll like a frt car due to the 12:1 gear reduction, but you should be able to roll it with your hand.
Modeling BNSF and Milwaukee Road in SW Wisconsin
BRAKIEA wild card and the one I chuckle at is using tooth paste on the gears and then running or some such fool thing.
And the lastest I have read, is using auto rubbing compound. Never done either.
A good cleaning is usually all it takes. Those gears are made from the "slippery" plastic.
Mike.
My You Tube
I took one of the trucks without the worm gear and put it on my four foot test track held at least a 15 degree angle and it doesn't roll a smidge.
Take it apart and clean it up. Take a close look at the gears, see if you can spot anything unusall with the teeth.
As Jim B. mentions above, especially if there is old grease in there, they are not going to free-wheel like a freight car would.
Some greases can become almost rock-hard as they age. I worked on a friend's brass steamer that would run only a short distance (inches, if that), then not reverse unless pushed, with some downward force. After a few inches in reverse, it would stop again.Upon disassembly, the grease between the teeth of the gear on the axle (the lowest one in the drive train) was discovered to be packed so hard in some teeth that it had to be removed forcibly with a small chisel. It's my opinion that the loco had sat upright for some time, years, if not decades, allowing the grease to migrate downwards, where it solidified.Once cleaned-up, and properly lubricated, it ran like a fine watch.
NorthWest Short Line suggests that for gears, including Delrin gears like those in Athearn diesels, LaBelle #102 heavy gear oil is a good choice.
They also suggest that if you feel it necessary to lap gears, toothpaste is a good choice, but advise that you take care to ensure that all is removed after the lapping has been done, and of course, then lubricate the gears before putting the loco back in service.
Wayne
I know that the problem isn't hardened grease. While it may shock people, I never have greased my engines. Part of the reason is that they were almost never run. For some of the engines I ran, that was the first time they had run in probably a year or two. (The old layout had very dirty track from lack of use.)
FRRYKidI know that the problem isn't hardened grease. While it may shock people, I never have greased my engines.
Ok..Let's look closer then..Have you use the NMRA gauge to check the wheel gauge? I have seen wheels that was rubbing the gear box on one of my trusty Athearn GP7s when it was new.
If you don't have the gauge then eyeball the wheels-you can plainly see if the wheel(s) is against the gear box or side frame.
For roughly 15 years I never owned a NMRA gauge..I use a old piece of 9" snap track and eyeball to gauge the wheels before placing on the car..
Don't laugh untill you try it since it acually works.
FRRYKidI know that the problem isn't hardened grease.
So by that, I guess your not even going to take the truck apart and inspect it?
Your not shocking anybody, as the slippery Athearn gears run just fine with little to no extra lube. It's the worm gear that usually needs a tiny bit.
Check your wheel gauge, as Larry suggest, and as far as "loosening up"? Nope, just running them gets them into the proper profile.
How would you go about " loosening up" the gears? File a little off each one? Get things too loose, and then you'll be having noise issues, and "bucking" movements, with the extra gear slop.
Don't worry about the 15% incline thing. Look at all the resistance, with all those little gears. You'd probably have to keep tipping the track until the truck slid down the hill before it's going to roll.
You should be able to put a finger on top of the worm gear housing, and push the truck around, easily.
Other issues that go with "using too much power", a dirty armature, drive shaft binding, a worn motor that takes a lot of amps to get moving, actually Athearn motors don't have to be worn out for that, some just take more amps than others, axle problems, where the axle goes through the little brass blocks, which is all part of the electrical path, including the way the blocks fit into the truck frames, wheels, whenever I "overhaul" an Athearn for DCC use, I replace the wheel sets with the newer nickel silver sets. Makes a big difference.
Maybe just run the loco, front and back, and then run it some more, and that will help "loosen" things up.
I wouldn't think the Delrin plastic that the gears are made from would be susceptible to that, but I'm not a scientist.
I've never heard of that. No comparison to wood.
And well never know, becuase the trucks apparnently aren't coming apart.
I am planning to take the trucks apart anyway. I also needed to take all the affected 35 drives apart anyway. (When I bashed the drives to fit under my Tyco GP20 shells, the power trucks ended up on the wrong side.)
Found yet another issue. I got one of the units back in operation but found something curious. What does it mean on an Athearn drive when the engine sounds like the power is cyclical? (Power goes louder and softer in intensity without varying the input power.) As usual, any assistance would be most welcome.
Never heard of that. Take the shell off, and follow it as it moves, watching the drive train, real close, and see if you can detect anything out of the ordinary.
Is this one of the locos you had the trucks in backwards? Athearn BB locos need to have the taller power pick up on the right side, once you determine the front of the loco.
Reversing them will have a definite difference in the way the loco runs.
Determining the front, as from the factory, should be easy enough from the head light mounting.
I think I finally have all the engines in running shape. A couple of them still have slightly high power draw but I can work around that. I still need a little bit of work on the F-unit but it is workable. (I need to improve it so that it works with the super weight. Given I run flatlands, the extra power is not truly needed but it would be nice.)
I ended up doing a lot to get the engines working mostly with the gears. On one of the trucks, I even discovered that the drive gears were cracked. In all the Athearn units I have played with, that's the first time I had seen that. (I had some spares on hand.) On some of the gears I ended up polishing them to catch any burrs. (400 grit sandpaper and only a couple of passes.)
I've discovered cracked gears on the SD45 and SDP40 models. It wasn't just a P2K thing.
I took the opertunity to replace the axles with the newer NS wheel sets.