Like many others on this forum, I get a great deal of pleasure simply repairing trains. This is my experience repairing a 342 Culvert loader that my Dad bought for me for Christmas sometime in the late 50’s or early 60’s. If you are experienced and masterful in this notoriously touchy repair, I hope you will indulge me while I share my experience with others.
All the pieces were there except for the string (well, I had a small piece of it) and the spring that supplies tension to the string. I bought the string from Jeff Kane just because the requirement is for a wax free nylon string, something I did not have on hand. But I forgot to order the spring! So I used a motor brush spring. It was close, but had the disadvantage of quickly stretching over time as the vibrator tugged and pulled on it.
After a thorough cleaning and reassembly, it sort of semi-worked – it was painfully slow with very little power, many times requiring a push to keep it moving. Adjusting the tension didn’t seem to help - as I added or reduced tension on the string/spring combo, it ran worse.
Finally the light bulb went off and I realized that this motor relies on the fact that when the vibrator moves rapidly toward the drive pulley & gear, it reduces tension on the string and lets the spring pull things back toward itself, but in so doing, it does NOT rotate the drive pulley because of the reduced tension – exactly how it’s supposed to work. When the vibrator pulls away from the drive pulley, it puts tension on the spring and string, and causes the drive wheel to rotate. The fact that mine had little power suggested the string was slipping on this part of the duty cycle. So I removed the drive pulley and thoroughly cleaned it with alcohol – there was plenty of oil and grease to go around, and I even found the brand new white string had black splotches where some of the oil had found its way. So being cheap, I cleaned the string with alcohol. But oddly, that alone didn’t fix anything. I next roughed up the inner groove of the drive pulley with the edge of a very small flat file. BOOM! That did the trick! I guess many years of the string rubbing on the inner groove of the drive pulley had worn it quite smooth, affording almost no traction. Immediately I had a ton of speed and power!
As I mentioned earlier, the brush spring stretched pretty quick, so in very short order I lost a lot of my newly gained drive power. Putting the tip of a screwdriver in between the center coils of the drive spring, then pulling and pushing to change the tension while watching the vibrations of the string, quickly revealed that lack of tension was the problem. With insufficient tension, I could see the string vibrating wildly. As I pulled on the spring to increase tension, the string vibration quickly went away, speed and power resumed. So I temporarily used another small piece of string to tie off two or three turns on the spring - BAM! Problem solved, power returned.
BTW, Lionel says to make that tension adjustment, bend the tab where the spring is attached until things operate well, but the tab is stiff and awkward to reach with normal hand tools. Lionel’s service manual also provides their process for installing a new string. But this was my temporary solution. I assume the spring will stretch again, so hopefully the spring I will get from Jeff in a couple of days (yep, ordered it!) will work better.
Then I had the other “normal” problem that everyone has - as the conveyor assembly would start moving back to grab another culvert, instead of smoothly releasing its load to drop straight down into the gondola, it hung on for just a split second, making the culvert drop a tiny bit late, off-center and crooked in the car.
The solution for me was to cut a small strip of cloth electrical tape (the kind your grandfather used) and apply it to the top, outer portion of the beam, right where the outer roller on the conveyor reverses on each run. This creates friction for the outer roller on the conveyor, holding it back and forcing the release of the culvert right on time. I went from a 1 in 7 correct drop to a 7 out of 8 correct drop instantly. Adding a 2nd much shorter piece of tape on top of the first piece, just inside of the where the outer roller stops did the final trick – it forms a very small step that will aid in making the release work correctly.
I should point out that when I cleaned the conveyor, I got rid of all oil & grease that the kid in me had applied years earlier. This is one of those devices where oil is really not needed and only serves to gum things up down the road. I added a small bit of graphite to both rollers initially, but ended up cleaning that off the outer roller as part of my attempt to add a small amount of friction and drag to force an on-time release.
I hope this helps someone else who has spent a few hours monkeying with a cantankerous accessory like this one!