my Athearn AC4400 (which is less than 2 months old) is making a strange noise. It’s a cross between a buzzing and grinding type of noise and it appears to be coming from somewhere near the rear. It’s not the shell vibrating. It’s most common when I first start the engine and it starts to clear up after a while but it still comes back for short periods. It will stop if I stop going forward and back up but a few seconds of backing and the sound comes back although it’s quieter------ let’s answer another question- my Atlas U33C makes a grinding when turning left. It is almost quiet when going straight. It is totally silent when turning right. Makes me think it’s the driveshafts. Thanks for your help[:)]
Let’s ask the obvious question first… Have you pulled the shells Off and made sure everything is seated properly?
Jeff
Also, once you get inside of it, does it have plastic or metal worm gears in the trucks?
I’m not a big fan of the red nylon worm gears Athearn has been putting in RTR stuff now-a-days. [banghead]
as far as the AC4400 i don’t even know where to look it could be coming from the rear truck but i don’t know what’s wrong-- the U33C i had to put back together a few weeks ago and i thought everything looked ok -it matched the exploded diagram
U33C, meaning older, non-DCC ready Atlas series, and not the new U30C’s?
Matt
ok…first of all…some of the older (90’s) Rivarossi’s had a plastic gear put in to save money.they put the plastic one in between 2 metal ones…I had to send mine in to get that gear replaced, because it sheared off a few teeth…from your description of the sound, I’d say HS2317 is onto something…I’m not sure where you’d get the right gears for it, but that’s where I’d start
first of all i fixed the U33C- the female universal joint that is on the shaft w/ the worm gear was crooked i bent it back into place w/ a small screwdriver i discovered this problem beacause the driveshaft was moving up and down quite a bit (when running)-- The U33C is a DCC-ready Atlas. It was new in 1996.
For the Athearn unit, check the end play on the worm gear shaft it could be tight or one of the thrust washers is missing. Have you added some weight to the shell? This helps in making it quiet down, and also check the wheels to, are they dirty? Dirty wheels and track can cause allot of engine noise at times, I have learned over the years to check this first, the engine may run great but have some noise problems do to dirty track and wheels. It might just need a good lube and cleaning is all too!
the Athearn has less than 10 hrs. on it and it’s making noise-- but last night i ran it for quite a while and it didn’t make the noise at all- it’s almost like something is dragging beacause when the noise starts the engine slows down a little and when the noise stops it speeds back up- the noise will stop if i slow it down and go very slow (15 scale m.p.h.) the sound is actually more of a cross betweeen fingers on a chalkboard and a grinding
“HELP! my engine is making a strange noise !!”
There seems to be a lot of that going around lately.[;)]
Have you removed the shell yet? Does the noise still occur with the shell off?
Jim
It sounds to me like one of the bearings is bad. Bad bearings can be quieted down for a while by putting oil in them. Have you tried oiling all of them?
You know I had that some noise come from My Athearn RTR Union Pacific AC4400 and it was bad. It was only of its 3rd run on our club layout. I was so pissed that here my $100+ engine was going bad so soon. I mainly just took it all apart and gave it a good cleaning. It’s not perfict but the cleaning did help some. Now I’m kind of sketchy when it comes to Athearn RTR
Sounds like to me somthing isnt seated right .you need to open the shell, and check all the worm gears ,and make sure nothing fell in the trucks ect then oil it,or grease it ,with a non plasic eating lube
Hope this helps
Carl
thanks i’ll try lubing the rear truck and worm gear-- zgardner18 $100+ for an Athearn RTR AC4400? that’s way too much. I got mine for $65
Check the nylon worm gear.I had an SD70 with this problem.Replaced with the older brass type and it ran smooth and quiet.Dan
its the track
i’m 99% sure the noise in the Athearn is coming from the motor itself. But the noise will go away after it runs for a while