I may dive into that science project on my old Athearn motor. The thing still looks brand new, but I think I burned up something trying to run it for 12 hours.
That's likely the Brushes and there ain't no DC motor out there (besides brushless motors) that's gonna do better. The other thing you can try is to clean the commutator. I've had a couple where just a little goo gone or similar and an eraser applied to the commutator made it work fabulously.
Ok, so looking on the athearn web site, you are saying that the 84086 with flywheels is a direct replacement for the athearn #84040 and will that motor use the same bar on top for power from the wheels as the old motor. What is that wire showing in the bottom of the picture? A lot of questions I know but I am new at this and know nothing about these motors. From the end of the flywheel to the end of the other flywheel, it is just about 3 inches.
Tramp - the 3 inch dimension matches up with what came out of my F7, so it's not the 'shorty'. Yoho - check me on this, but I would assume that the wire shown at the bottom of the picture is needed for correct hookup in a DCC loco? From what I observe in the picture, the motor is indeed a direct drop-in replacement. Clip the top band from your old motor onto the new one and it should be good to go.
Thanks, I just received an email from Athearn and they are telling me that the 84087 with the flywheels is the update motor for the Gp9. They list other parts with it - a 6 pack of drive shafts and a worm assembly. Wouldn't the drive shafts & worm assembly from the old motor fit the new one. Thanks again for your time and answers.
I guess the best answer is - "it depends". The Athearn F7 that I replaced the motor with the NWSL motor kit is a relatively new one, bought in 2009. The flywheels have hex shaped ends that match the hex ends of the drive shafts that connect to the worm assembly. if your drive shafts connect this way, I see no reason to get new ones. I can't say for sure because I don't know that your older (35 years?) GP9 drive shafts and flywheels have this hex-shaped connection point. I'd say the same regarding your worm assemblies - I would think they would be fine but the problem is I don't have an old Blue Box loco to eyeball here. I know of a website that has old parts diagrams, maybe I can find it there. In the meantime, anybody else have experience with OLD Blue Box drives in this regard?
Tramp - I got the links below from http://www.hoseeker.com/athearn.htm The first one shows the hex drive I mentioned. It's a late (2004) F7. Check out the flywheels and drive shaft ends. See the 'hex'? http://www.hoseeker.com/assemblyexplosionAthearn/athearnf7abrtr2004.jpg Now check out a 1975 GP9 parts diagram below that I think shows what you have. Check out the flywheels and drive shafts again. No hex. The worm assemblies are different too. So based on these diagrams, you WILL need the worm assemblies and drive shafts that Athearn referenced for you if you get that replacement motor. It's still an easy drop in replacement, but yeah more parts to get. http://www.hoseeker.com/assemblyexplosionAthearn/Assembly Explosion Athearn GP9 1975.jpg Note: I could not find a late 'hex drive' GP9 on the site, so I'm thinking there wasn't one. And if those drive shafts are the same ones that fit the F7, I have a drawer of them. PM me your address and I'll drop a couple in the mail.
the difference between the 87 and the 86 is that the 87 comes with a replacement power clip and the 86 comes with a DCC clip, but you already have all the clips from your original, so you don't care. What you do care about is the 87 is reported as sold out while the 86 says in stock. Trust me, they are the same. Here's a picture of that wire attached As for Hex drive, I would double check with Athearn. Looking through the website, they have the pictures taken in such a way that you can't tell if it's the classic coupling or the Hex drive coupling which is really frustrating.
"What you do care about is the 87 is reported as sold out while the 86 says in stock. " You are correct about being shown sold out, but the Athearn email I received yesterday said the 87 was in stock and listed the price.
Same motor either way. Good advice to double check with them on the hex drive issue. I'd bet they are, but hard to say for sure.
Picked up a "new" undec BB GP9 at a train show yesterday. All 4 axle gears were cracked. And other than that, running not so good. After replacing the axle gears, cleaning/lubing the trucks and giving the commutator a good cleaning with alcohol and a Q-tip, this loco is running better than new. I think I might reserve that other NWSL motor kit for another project....
