This past weekend I picked up a 8305 steamer at a yard sale, I believe this is from the early 80s or late 70s. Not 100% but may have come in the Milwaukee rd passenger set. The shell looks very similar to a postwar 2037. Anyway When applying power the engine runs perfect forward but in reverse it only hums and vibrates. I opened the engine and it has a 2 position e unit which is in fact cycling. Seams like the motor is fighting itself in reverse, I was thinking maybe ts a DC motor but then I don't think I would have it running so well in forward. Any ideas what I should be looking at next? I don't believe its a e unit issue because it would most likely just be silent when in the reverse position rather it is vibrating like mentioned.
Replies sorted oldest to newest
Hello. Technically, it’s a universal motor, which can be run on AC or DC. But, Lionels intent was that it be run on AC. It is possible that either E-unit is damaged or the field winding is damaged. Since it runs forward, I doubt that the core winding is damaged. How to repair: for me that would get a bit wordy. So, respectfully, I’m not going to go into that here. Basically, a wire could be broken or damaged. That could include a damaged drum in the E-unit. FWIW, I came across another thread regarding an 8305. I came across it while googling the engine number. But you could probably use the search function for this website and find it. I didn’t read it as it was a long thread but basically it talked about poor performance.
In my experience if there were damage on the contacts of the e unit the motor usually does nothing at all.
Look at the fine wires from the field coil. Sometimes they can touch the metal aluminum frame of the motor. If one is touching, you will get the results you have, runs one direction, but not the other. Also check that the brush wells don't touch the body. Finally, is the motor staked tight, in other words, you can't shift the motor frame in your hand left or right.
You can also simply have a dirty contact in your 2 position e-unit - it will still make noise as you stated, but it can run badly or not at all.
A very simple thing to try is to wet a Q-Tip with alcohol, then swab both e-unit contacts - the e-unit contacts are simply the back side of the solder stakes on the e-unit. It takes less than a minute and IMO it's worth trying.
I had a similar problem with my 8305 Milwaukee Road locomotive. It would sometimes not work in reverse, or would stutter in reverse. It turns out it was a bad/cold solder joint for one of the wires connected to the motor assembly.
It took me quite awhile to find the problem, as I was originally thinking it was a problem with the e-unit. I finally found the bad solder connection by doing a "tug test" and just tugging on the wires to the motor. One of the wires came loose after tugging on the wire. I re-soldered the wire to the connection point on the motor and have not had a problem since. Not sure how prevalent this problem was for these locomotives, but I'd check that out as the cause of the problem. Here is a diagram and area with the wires and solder connections to check:
I first observed this issue back in the early 80s, and remember being frustrated as a kid that my locomotive was having this problem. I finally figured out and fixed the problem 35+ years later.