Hot 736 Roller

CRC 2-26 or similar on the pickup roller may help. It also may be worth replacing the tension spring with a new one (or the whole assembly for that matter)

Another good thing to try with high resistance joints on rollers is something like Deoxit-D5.  I buy the spray can and then spray it into a small needle point applicator for more precise metering and less mess.

Thank you for the advise, guys.

I have CRC QD Electronic Cleaner, which seems to clean all of the gunky, gritty parts very well with a toothbrush. That is one product that I can find locally. Do auto parts stores usually carry the CRC 2-26, which looks more like a lubricant to me? I will look for that, although I prefer to buy locally when I can.

I also did not put any oil in the little hole in the top of the casting in the motor to lubricate to worm shaft. I will do that today.

Thanks again for the advise, I am learning a lot because of this forum.

Steve

CRC 2-26 is available from the orange home improvement store: https://www.homedepot.com/p/CR...cant-02004/100398344

The idea of the replacement tension spring for the front roller intrigues me-when the loco runs, I see heavy sparking from the front roller, and none from the back. The front may have less than ideal contact with the hot rail, although the tension on the spring on the front roller does not seem weak to me.

Steve

I'd start doing the easy thing, shoot it with some contact rejuvenator first and see if that solve the problem.  If the spring doesn't appear to be any weaker than the other one, I don't know that replacing it is going to have a major effect.  Maybe replacing the whole roller assembly is called for.

I’m not 100% certain, but I think you can remove the roller from the pickup assembly. One side should be flared and the other not. Bend the not flared side away just enough to release the pin. Then the other side to clear the roller. You should be able to take the roller off. Clean the pin an the inside of the roller. Than a small drop of conductive lube. Reassembly is the reverse. Use a pair of channel locks to gently squeeze everything back together. Be certain the roller turns freely. That should do the trick.

Chris

LVHR

Thank you for all of the suggestions, I am going to see if I can find some conductive lubricant today. Removing the roller and cleaning the pin sounds like a good trick.

@Steve1964 posted:

The idea of the replacement tension spring for the front roller intrigues me-when the loco runs, I see heavy sparking from the front roller, and none from the back.

That would indicate, along with the heat, that the problem is with the rear roller not working, and the current instead all being carried through the front roller.

The rear roller is the problem.

Easy to check with a meter, and I'm pretty sure if the one roller isn't working, this would be stopping on every switch!

Hold your engine upside down in your right hand. Pick up a piece of straight track with your left hand, and mate it with the engine drive wheels. Now look carefully as you pull the track away from the rear roller, does it appear there is/was good tension between the roller and the center rail? Do the same with the front roller to compare the two. Does the rear roller lose contact almost immediately as you pull the track away? Does the front roller remain in contact with the center rail a good bit longer than the rear roller? If so, something may be blocking full movement of the rear roller. With either light tension on that roller (or even full tension, but limited engagement), that would explain the symptoms you are seeing.

George

@ADCX Rob posted:

That would indicate, along with the heat, that the problem is with the rear roller not working, and the current instead all being carried through the front roller.

The rear roller is the problem.

Hey Rob, I lifted the locomotive off of the tracks and touched both the front and rear roller with alligator clips hooked to the center rail, they are both picking up. Thanks for the suggestion, I tried this early on.

Hey guys, thanks for all of your generous advice. I tried to find some conductive lubricant today, none in any local stores. I live in Middle Tennessee, no large towns around. I was rolling this loco on the tracks with my hand, and I heard a scraping noise. I got a flashlight and noticed that neither roller was turning all of the time, sometimes they were both sliding. I suspected that there could be some corrosion or other gunk on the pins. I pulled the front roller off, and I noticed lots of black crud on the pin. I cleaned the pin with my CRC Electric Cleaner and a Dremel, and cleaned the roller too. I think that this made the loco run better, even though I have no conductive lube. The loco pulls an 8 car train at 9.5 volts with spirit in the straights. The roller still gets hot, but it takes longer now to do that.

I will continue looking for the lube, and I appreciate all of the help. Steve

If the pins were cruddy and looking corroded, maybe it's time to replace the roller assemblies.

Hey John, would you just replace the entire assembly with a new one? I noticed that there are two screws that hold it on, do I just remove the screws and the whole assembly comes off, that easy? I don't see any wires soldered into it in the Lionel Operating manual. It certainly does not bother me add a new part, and keep the old one in a drawer.

Thanks

The 736-16 assembly is the easiest replacement. Generally, there is no solder as the 671-200 is sandwiched and makes physical contact when the assembly is screwed on.

In further review and for completeness, if one has 1957 or later 736, then it uses the 746-26 collector assembly which has a single screw and a soldered connection.

This is the connection to the collector.

To tell you the truth, it's been so long since I've seen one of these, I'm not sure exactly how it connects or is kept in contact with the collector plate, but it should be obvious.

I'd just buy the 726-16 and the 726-101 if it looks like it's not in good shape.

@bmoran4 posted:

The 736-16 assembly is the easiest replacement. generally, there is no solder as the 671-200 is sandwiched and makes physical contact when the assembly is screwed on.

That sounds easy, thank you for the advice.

@gunrunnerjohn posted:

This is the connection to the collector.

To tell you the truth, it's been so long since I've seen one of these, I'm not sure exactly how it connects or is kept in contact with the collector plate, but it should be obvious.

I'd just buy the 726-16 and the 726-101 if it looks like it's not in good shape.

Thanks for help,  John!

Over the years, I have experienced weak roller springs, the result of a short circuit that caused it to overheat.

@RJR posted:

Over the years, I have experienced weak roller springs, the result of a short circuit that caused it to overheat.

I actually suspected this earlier, and made a shim that forced the front roller to stay down on the middle rail. I ran the loco for a while and the roller got just as hot. I don't think that a weak spring is the real issue here. But thanks for the reply.

Steve,

Did you pull both rollers or only the front one? I'm with Rob on this one: Pull the back roller and clean it and the pin if you have not already done so.

Chris

LVHR

Chris, Thanks for the input, I will pull the rear roller next. I am trying to get some conductive lubricant headed my way, I have put my wife on that chore-and she never fails. What I have done has made a real improvement in the way this piece runs, and I think I am on the right track, thanks to this forum.

Steve

Hey folks, I found CRC 2-26 at Home Depot today, and bought two cans. At $3.48 a can, it was definitely one of my wisest purchases lately. I pulled both pickup rollers on my ailing 736, and polished both pins as well as I could with my Dremel. I gave both rollers a bath in some mineral spirits, dried them, and gave them and the pins a shot of 2-26. I let everything dry and put it all back together, and what a huge difference it made! I ran the 736 for an hour pulling 6 cars, then checked the rollers. They were both barely above cool, with the front being no hotter than the rear. I think this is huge success for me.

I wish to thank everyone here that gave me instruction and suggestions for this project! I took a 3 window 736 that was obviously sick, and now it runs as good as anything that I have, including a few pieces that I have paid repair bills on. And I have no training other than what I have learned on this forum, a few books, and asking questions at train shows.

I look forward to my next project!

Steve

@Steve1964 Thank you for following-up on this and posting the resolution.

Cool, glad it worked out.  The contact rejuvenator is certainly something to keep in your bag of tricks, I've fixed a bunch of stuff with a simple spray.

@gunrunnerjohn posted:

Cool, glad it worked out.  The contact rejuvenator is certainly something to keep in your bag of tricks, I've fixed a bunch of stuff with a simple spray.

John,

Years ago I bought a 2065 Lionel from a guy at the Nashville Train Show, and it was basically the same scenario. I cleaned it up and put brushes in it, and it ran good, but it always ran hot. I finally took it to a guy that tuned it up and charged me $65 to do it. I certainly don't mind paying someone for their time and expertise, but I would rather be able to do it myself. To me, that is part of this hobby.

Hopefully this post on my old 736 will help someone else.

Yep, lots of old jokes about expertise in all sorts of professions.   It's certainly true, sometimes it's just knowing what to do for a specific issue.

Steve1964, I'm glad to hear that it all worked out. Congratulations on getting back to operational status!

Chris

LVHR

@gunrunnerjohn posted:

Yep, lots of old jokes about expertise in all sorts of professions.   It's certainly true, sometimes it's just knowing what to do for a specific issue.

"Nothing is so easy as the job you imagine someone else doing!" I've stolen this too many times to count.. Says it all, IMO..