I bought a set of these F7s about 10 days ago.
Coffee grinders make similar sounds.
Most say they quiet down after their broken in.
36 hours, no difference. bummer
After reading here, and other places, I see that this is common.
So... I did a lot of hunting, and finally found something useful.
On an individuals website, he said that he uses Soft-Scrub on his
BRASS models. ( to quiet the gear noise ) Eureka!
It works! 90% of the offending noise is gone. Yes, the motor itself
is still noisy. But I can now hear the wheels go over the rail joiners, other
locos, etc.
How to do it:
1: Take the body and the fuel tank off
2: Remove the side frames from the trucks
3: Take the bottle of soft-scrub (shake it up first)
and put two drops right from the bottle into the
bottom of the truck-gearboxes. Then add 1 drop of oil.
(Keeps the soft-scrub from drying out)
4: Put the side frames back on the trucks
5: Run the loco at about 50% ( I used a DC pack for this )
for about 15mins forward and then 15 mins. backward
6: Remove the locomotive from the track and disassemble
you do not need to completely take it apart, just get the trucks out
7: Use hot water and an old toothbrush, paintbrush, etc.
to clean out the trucks
8: Re-assemble locomotive and lubricate it. Not too much.
9: Enjoy the quiet.
My A-unit had to be done twice, it was incredibly noisy though.
I have heard that Pearl-Drops tooth polish works too.
I think more people would have soft-scrub on hand than pearl-drops.
Sorry for the book. I hope this helps someone out.
Thanks for the tip! However be careful not to break off the coupler end of the truck side frame unit when removing it from the gear retainer section. I broke mine while changing out the Rapido couplers for Bachmann dummy knuckle couplers. Bachmann has the replacement part part, or you can tap and use a MicroTrains screw to repair it, like I did after my boo-boo.