397 Coal Loader Cam Stuck

Unless my memory has failed, the shaft with cam assembly stays in tact.  Lift out the shaft assembly with beam assembly, and remove idler roller on front of beam (remove separator pin).  New belt just slips on. 

I learned the hard way that Liquid Wrench (non-aerosol) has a finite shelf life. So if your container is old, it might not be as effective as it once was.
PB blaster might work better.

Heat might work, but you'd need to do something to keep the heat from traveling along the shaft, and melting any plastic parts it is in contact with.

I ran into the same problem with a stuck cam. In the end, I ruined the shaft and had to replace it.

Good luck

Only the cam furthest from the motor has to come off.  I can't help you with removal techniques because my 397 has the cams floating freely keyed to the shaft so it's a real cinch job for me.

Thanks, but still no solution.  Susan, it looks like the shaft needs to come out so that the  plastic tray can by removed.  I don't see any way around that.  No one else?

quote:

I can't help you with removal techniques because my 397 has the cams floating freely keyed to the shaft so it's a real cinch job for me.

The cams are supposed to slide off easily. Once in a while, a loader turns up with stuck cams.

I let the liquid wrench work overnight, but it is an old can.  Did anyone use a tool like a gear puller to try to work the cam off?  Some rust, but not heavy.

I would try PB Blaster.  Seems to be more effective than LW in my opinion.  Can be found just about anywhere including Dollar General.  Patience is the key and liberal amounts of PB Blaster too.  Gentle tapping in both directions to get it broke free and go from there.  Good luck as I used this for one I had and it worked!

See this thread on using electrolysis to remove rust both on the shaft and inside the bearing in a very short period of time. The process is quick, does not harm plastic, non-rusted metal, or paint.

Larry

Thanks for the detailed instructions wolverine.  I will try this next weekend.  The electrolysis is very interesting too, but I would probably just get a replacement shaft and cams before doing that.

You're most welcome. Hope it works out and you will post the results. When a post-war 397 is tuned up and the "coal" is properly sized, it will work very well indeed.

A few quick points:

1. If it becomes necessary to purchase new cams, always buy them in matched pairs. They must be identical: consider the profile of the cam to be a clock-face. If you orient the points of the cams at six and twelve o'clock, sometimes the closest corners of the square hole will be at two and eight, others at three and nine, etc., more or less. A "two-and-eight" cam and a "three-and-nine" cam will not work together. Properly matched, and run at slow speed, the device should sound like TAT.........TAT.........TAT.........TAT....ect., whereas un-matched cams will sound like ta-tat........ta-tat........ta-tat.......ta-tat.....etc. and the device cannot work properly. Even if they are matched but positioned on the shaft 90-degrees out of phase they will sound like tat..tat..tat..tat..etc., that is, twice as many tats per unit of time than when things are positioned correctly. That won't work either.

2. To reduce the chance of things freezing-up again put a light coat of good quality grease on the shaft and the inside surfaces of the square hole in the cams. I'd use Red 'n' Tacky or even a little water-proof wheel-bearing grease such as they sell for boat trailer bearings.

3. Once you have it apart, and need to order new parts, consider replacing the rubber "Flexible Coupling" part number 397-29 in some reference books.

4. You might also open up the gearbox. If the grease is old, hard or waxey, clean it out and replace. Again, I'd use Red 'n' Tacky. 

I realize that these posts are wordy, but please forgive me. The 397 has always been my favorite Lionel trackside accessory, especially when combined with the 456 Coal Ramp and some bottom-dumping hopper cars. On our most elaborate layout (alas, long gone!) we also had a 97 Coal Elevator and some side-dumping hopper cars too. Man, did we move coal!

Only to commiserate, jim.  I got a 397 at a bargain price ($19), but it also has a bad case of stuck cam.  No penetrating oil will budge it, and for certain, no "light tap" is ever going to break it loose.  Nor even a heavy tap.

I'm ordering some new parts from Olsen's, but in the meantime, I at least got the 397 running again.  The ancient belt just needed some rubber-roller dressing (used for printers) applied to the back, then half an hour of running to flex it in.

jjm,

Have you been able to resolve this problem? If so, how?

wolverine

I don't know about Jim, but I can at least tell you how I resolved the same problem.  I ordered a new shaft/coupling/bearing assembly (plus a few other missing parts).  Then I cut off the end of the old shaft, stuck cam and all, with an X-acto saw.  I had to be careful not to damage any of the adjacent plastic parts with the saw, but it didn't take long.

Once I had it off, I tried to see just what was causing it to stick, and how badly jammed it was.  I put the cam on a vise and used a roll punch to carefully hammer the stub end of the old shaft out of the cam.  It took a lot of hammer blows, but eventually I was able to pound it out.  Inside was heavy rust, solidly fusing cam to shaft. 

With the old assembly out of the 397, it was a fairly trivial matter to install the new shaft and ancillary parts.  I put in the new belt, added the missing platform return spring, lubed everything, cleaned up the outside and applied power.  My 397 worked perfectly, probably for the first time in years.

The moral is, sometimes the end cam can be so solidly corroded to the shaft that none of the usual tricks will free it.  The only course when that happens is to cut it off and replace it with a new shaft and cams.  And put some oil on the shaft, to prevent future seizing.

Very clear explanation. I thought you were going that route when I saw your post about ordering parts. Glad it worked out. The only thing I might have done differently would have been to use a little grease,* or perhaps something marketed as an "anti-seize compound," inside the new cams rather than oil -- but your oil should last a good while. 

If your 397 gets used, as opposed to stored, you will probably need another belt change before the cams freeze up again.

I'd still like to see an update from jjm.

* Red 'n' Tacky, perhaps....

Footnote: Have started a little research project regarding the efficacy of various brands of penetrating oil, and will post about it if and when I learn anything, if anyone is interested. 

wolverine

PB Blaster and time.  OR, fill a bread pan with Coca-Cola and immerse the entire shaft assembly and tray, let it soak.

PB Blaster is certainly highly regarded in some circles, Rob. There is at least one group of devotees who seem to prefer something called KROIL from Kano Labs, and another who swear by a home brew made by mixing Automatic Transmission Fluid and Acetone, which sounds wicked and very dangerous, but all the returns are not yet in.

I have no experience with KROIL. Website: http://www.kanolabs.com/

wolverine

I've used Kroil quite a bit on guns and auto parts. It's good stuff, but not miraculous. I did use it to free up some tools that didn't respond to anything else. I've been told that Kroil was originally formulated as a cutting oil and I've also used it for that. 

Well I tried to carefully tap the cam off as suggested.  It was really stuck.  Problem is that it was so fused that it eventually just broke apart.  Oh well, new one goes on next.

Sorry and a bit surprised that  it didn't work out. Please heed my cautions (above) regarding the absolute need to get perfctly matching cams. This might involve breaking the other cam off too. Try not to damage the square drive shaft because replacements can be somewhat difficult to find.

Now that you can get things apart, someone else may have a good method of cracking-off the other cam with the least possible danger to the shaft. (Based on your experience so far, I would NOT try to slide the second cam off the shaft: break it too.)

Thanks for the update. I'd be pleased to hear how if finally turns out. Good luck!

wolverine