Just thought I'd jump in, as I run a lot of BB locos. I discovered cracked axle gears on two SD45's and on one SDP40. I bet that is your problem. I think thoses runs of Athearn were all about in the same time frame. You'll also get a slight "jumping", which is pretty much the give-a-way on the cracked gears.
As the OP mentions, what cracks is where the axle slides in.
When I "overhaul" an Athearn BB loco, one of the many things I do is replace the axle/gear sets with new NS wheels. You can by the sets from Athearn. I don't know the part number right off hand. You just have to check wheel gauge, and drop them in.
Mike.
My You Tube
NVSSR,
I'm willing to bet that is Your whole problem. I have never heard of split axle shafts though on the newer Athearn's........anything I guess is possible today.
I still find that strange though. I have six Athearn BB SD40-2's, two from the 60's, four from the 70's that all have original axles/gears and wheels, that all run great, even together. All I did to them was change the lighting to LED's, isolated the motor from the frame with the five point wiring system......also have many other engines By Athearn, none of which had a cracked gear problem.......Im lucky I guess! I run DC.
Good Luck!
Frank
The gears all have a matching tooth count. Either the teeth are too thick or I keep missing something. But right now I have another easier to fix issue. The gears on the wag are split 4 of the 6 axles need new gears. The point where the axle of the wheel slides into the pocket for the gear is what is split the gear isnt split. From What I can see. Might be the entire problem. Never had that gear split on any Athearn before. Wonder if this is something with the new china made low tower designs. Off to ebay for parts.
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
Just to add to Henry's post.............
https://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm
If the axles end's are polished and bronze is clean, there is no need to lubricate them.
Take Care!
NVSRRI have Dielectric grease that I have been putting on the bronze bearings both in the axle pocket and where it conacts the metal plate. I find that works really good.
Dielectric grease prevents corrosion, it does not conduct electricity.
Henry
COB Potomac & Northern
Shenandoah Valley
I have Dielectric grease that I have been putting on the bronze bearings both in the axle pocket and where it conacts the metal plate. I find that works really good. I can see the gear ratio would be an issue if the wrong WAG is used. I am betting that is what it is
Thanks
Wolfie
Those are Bronze bushings/bearings not brass....bronze is a harder alloy. Also putting oil in them is not such a good idea...they get their power pick-up through those bushings/axles.
Yes......definitely check the tooth count on the axle gears. The Athearn BB's had a 12:1 gear ratio....all newer engines and a lot of new parts have the 14:1 ratio, which means there will be more teeth on the axle gear. At least one more. Theory is.....they sacrificed top end speed for better pulling power at the low end.
You mentioned that you adjusted the bearings. Did you check the gauge of the wheels? They could be rubbing against the side frames or even the bearings. Make sure the brass bearings turn free and use a LITTLE bit of Labelle oil on them.
I'm assuming you are using Athearn 42" wheels, part number 40029.
Good luck,
Len S
The gears turn free in the tower. And have been degreased with fresh grease being applied. It is those gears on the axles that cause the issue. never thought to check them for pitch and tooth count. Those WAGs could be from older tower designs and not be correct. So no, I am not sure they arent binding.
Are You sure they have the correct amount of teeth on the axle's or are of a different pitch than the drive? Like they don't go deep enough and bind.
Put some LaBelle Plastic compatible Grease #106 on them....not oil. See if that helps. Without the worm gear on in the tower, they should all turn very free.......check the mesh of the worm and gear in tower also.
I found one of my bluebox 6 axle units was drawing high voltage and running very stiff. I pulled the trucks and dissassembled one to go over the truck and gears. Clean and remove flashing, make sure holes and such are clean and sized right and round again. All the gears went back in and are much looser. But here is the issue the axles go back in and it get stiff. It is more loose rolling but still stiff. The bearing and such were also adjusted. Something with the axles makes it stiff. The trucks are newer version lox height towers. I have torn down many blue box trucks nd never had this problem They were all high tower. This is the first low tower in the fleet.
Is this a new problem with newer trucks getting stiff do to a wear and tear issue? Liek the derlin is a bad blend and swells or wraps Really at a loss.