Sounds like you need to clean the brushes and commutator plate. Take the brush housing off with a screw driver and be careful as the springs and brushes may fall out when you pull the cover off. Clean the armature plate with a pencil eraser, do not use a wire brush! Clean the brushes, if there is enuff left to clean or replace if needed, with a pencil eraser first then check for being flat across the tops, if not flat use a mild sandpaper to remove the nicks or burrs, brushes can be cleasned in alcohol but must be dry when re-assembling everything.
Lubricate all wheels at the axle points or as close to the axle points as possible, even need to lube the small driven wheels up front and trailing wheels in the back of a steam loco, lube the small center rollers too-the little silver wheels underneath the loco. You can clean the wheels with a dremel tool with a wire brush, but make sure the motor is assembled first or a rag stuck in the hole where the armature goes to keep dirt out of the motor area.
Lee F.
God bless TCA 05-58541 Benefactor Member of the NRA, Member of the American Legion, Retired Boss Hog of Roseyville , KC&D Qualified
Thanks Chief!
I have two 224's which are baby Berks, one is a 224E pre-war, the other is a post-war 224, the rear of the cab design is differant on the two 224's. Also have another steam loco in the 224 family. I have repaired a 235 scout locomotive or at least tried to repair one as they are very fussy about getting repaired if you can repair one, used Aurora H.O. race car brushes in the 235 and pen retracting springs. Still have the 235 but have put a new motor under it a few years ago as I was given a more recent scout loco with a junk shell, now the 235 is a 2-4-0 with a D.C. motor, instead of a 2-4-2 with an A.C. motor.
Here are a couple of "shots in the dark" that you might try. 736 Berks obviously have 8 drivers on 4 axles. The front three driver axles are non-powered; only the back axle is geared to the motor. I'm not sure how far you went with disassembly.. did you remove all drive rods, and the motor. If you just removed the drive rods, that is why you only detect some resistance in the rear set of drivers, because they are still geared to the motor. If you removed the motor as well, then you likely discovered that there is a lot of hardened lube in the gear well. That needs to be removed, both from the axle gear and the gear well. Clean the worm gear that is on the end of the motor shaft as well. When you re-seat the motor, make sure that the motor shaft gear meshes correctly with the axle gear. Add some new lube to this spot. If this doesn't help, check that you have re-attached all drive-rods correctly, especially the ones that have the eccentric cranks. If these aren't fastened correctly, they will bind (sometimes at the strangest moments.) I'm no genius when it comes to engine repair, but I have tried these methods on several engines, and they have run smoothly ever since. Good luck!
Excellent tips as I am about to begin work on my 736.
Jim
Modeling the Baltimore waterfront in HO scale
jaabat wrote: Excellent tips as I am about to begin work on my 736.Jim
OH NO!!! One night's lesson on train repair and he is now Dr. tinker Jr.
Like I said, it takes a lot to move these guys. Probably the comutator is gummed up like Lee said.
jmsiv,
I agree with what has been said above, and a good cleaning/lubing may fix it. Although heavy, a 736 should fly at 15 volts, which would be full throttle on a 1033, for example.
In my experience, the gearbox (as well as the upper and lower driveshaft bearings and the shaft itself) might be thoroughly gunked up with that old orange Lionel postwar grease that has dried to a solid chunk, and has transformed into a sticky rather than a slippery substance. It may require mild solvents, such as mineral spirits, to get the old lubricant completely off of all the moving parts. If you neglect this step, new lube won't help much. The excessive heat that you describe is not a good thing. Once cleaned and re-lubed the loco should run much cooler.
Your report that the lurching happens "mostly when going around turns" suggests that there may be too much side-to-side play in the drive wheels, resulting in intermittent binding.
Sometimes this can be corrected (or at least diagnosed) by applying a thin layer of grease to the backs of the wheels in order to reduce binding. With four drive wheels, a 736 gets more sideways thrust on the wheels than a loco with 3 or 2 drive wheels does, but should not have a problem on 054 track.
If there is really too much play, some folks have corrected it by inserting a shim on the axle between the wheel and the frame. This tightens the drive assembly up closer to original tolerances and helps keep the spur gear centered on the worm gear on the end of the motor's drive shaft.* If you pop off the cover of the "gearcase" you may be able to see what is going on. A 736 should have no problem whatsoever with 054 curves as long as the track is in proper gauge.
The need to "shim out" the drive wheels on older locomotives has come up on this and/or the other forum several times. A search of the theads might give you more info than I can.
*Still another possibility is that the worm gear is meshed too tightly with the spur gear. Some shims under the motor mounting points may be necessary; and it may take some experimentation to determine how much shimming to do and where to do it. I believe there is some guidance in the Service Manual, available online.
bfskinner wrote:...Your report that the lurching happens "mostly when going around turns" suggests that there may be too much side-to-side play in the drive wheels, resulting in intermittent binding...
...Your report that the lurching happens "mostly when going around turns" suggests that there may be too much side-to-side play in the drive wheels, resulting in intermittent binding...
This is the likely cause.
The shimming of the drive axle can also be done inside the gearbox - between the worm wheel & the chassis. Shim the axle to center the worm wheel with minimum side-side play but without binding. Use a good synthetic grease in the gearbox.
Proper placement & holding of the worm wheel in relation to the worm gear on the armature(& naturally putting the wheels in proper place too) is so much more critical than the slight additional friction of axle shims against the chassis.
Use synthetic oil on the axle bearings and, important especially on the single-worm drive steam locos, the side rods/bearings. The motor power is transmitted through the side rods on these, they are not on spur-gear driven engines(the rods are just along for the ride on these).
Rob
You would have to mark the wheels or be prepared for a lot of trial and error.
You may get incorrect advice that the drivers should be quartered exactly, that is, set with their cranks 90 degrees apart. In fact, the quartering can be significantly off from 90 degrees and the locomotive will work just fine. What is important is that the quartering error be the same from axle to axle. Also, keep careful track of which wheel and axle goes where, since the splines may be cut into the wheels by the axles at random angles from axle to axle: Only the angle between the cranks can be counted on to be consistent.
If you do pull the wheels, be careful to put very little force on the flanges with the puller. Instead, rely on tapping the center of the puller to drive the axle out of the wheel. You shouldn't need Loctite for replacing them. Press them on at the hub, not the rim. Don't press the hubs on both sides at the same time. Instead, press a hub on one side and an axle end on the other side, so that you can get equal penetration of the axle into both wheels.
However, it is practical to shim drivers without pulling them. Use washers with a slot cut just narrower than the axle diameter, so that you can just force them on but they won't fall off.
Bob Nelson
The splines end at some point; but there is no shoulder that is meant to set the gauge. You should probably measure it before you pull. It might be easier to measure the offset between the axle end and the outside hub surface, rather than to measure the gauge directly.
I press wheels on with a large vise. I remove the jaws and put a couple of machine screws into two of the opposing mounting holes. One has a simple hex head, which presses on a wheel hub. The other one is ground down to slightly less than the axle diameter and presses on the other end of the axle, through the hub if the wheel on that side is already on the axle. This is how I equalize the penetration of the hubs by the end of the axle.
It is possible to wind up with a crooked wheel. This is a particular problem if you are trying to increase the gauge and can't get as much of the axle into the wheel as you would like. This can be corrected while pressing by shifting the screw that is pressing against the hub to one side or the other of center until the wheel is true. Spin the wheel frequently to be sure you catch any crookedness before the wheel is all the way on.
Bob, the quartering is pretty important on the single worm locos. With power being distributed through the side rods, if the timing is off from the 90 degrees, the load will be uneven, resulting in binding as the load is transitioned unevenly L-R & R-L.
On double worm or spur gear drives, it doesn't matter, the rods are all for show.
If at all possible, use Jesus clips(e-ring clips) that are sized to snap over the axle for shims inside of the gearbox. There are Lionel parts that are pretty close - I have a couple parts drawers full of them. Avoid pulling the wheels unless absolutely required.
Rob, I meant my statement to apply to a locomotive with a single worm wheel as well as one with individually driven wheels or axles. As long as one side rod is reasonably far from dead center when the other is at dead center, the thing will work. A 10-degree quartering error is no big deal as long as it is the same on all drivers.
But if the quartering errors are not the same, either type of locomotive will bind, even though the rods are all for show. The only advantage the latter type has is that, since the rods carry no load, the rod bearings can be made sloppy enough to tolerate some amount of quartering variation.
With the greatest of respect for all the suggestions made re: shimming and pulling wheels, why not try the simplest method first. You have cleaned the axle and motor shaft gears, and, I assume, re-assembled the motor to the chassis. Leave ALL the drive rods off for the time being, set the engine on the track, and run it on the sections of track you normally do. It will run without the rods. If it doesn't lurch or stall, then I would say the trouble is with the drive rods. Here's hoping...........
initagain wrote:...Leave ALL the drive rods off for the time being, set the engine on the track, and run it on the sections of track you normally do. It will run without the rods...
Well, actually it won't run very well. On all 736 locos, only the rear most wheels are driven by the motor, so only the back drive wheels will turn w/o the side rods. How much of a diagnostic tool this would be is debatable.
The binding on turns is the clue here. If the drive axle has .10" side-side play as reported, that's the problem. That's a LOT. I use around .010" when checking this measurement - just shy of tight. If the wheels are pulled into the magnets, that's a lot of drag.
lionelsoni wrote:Rob, I meant my statement to apply to a locomotive with a single worm wheel as well as one with individually driven wheels or axles. As long as one side rod is reasonably far from dead center when the other is at dead center, the thing will work. A 10-degree quartering error is no big deal as long as it is the same on all drivers.But if the quartering errors are not the same, either type of locomotive will bind, even though the rods are all for show. The only advantage the latter type has is that, since the rods carry no load, the rod bearings can be made sloppy enough to tolerate some amount of quartering variation.
I'll accept that. It's not as critical as when the rods are actually powered by reciprocating pistons and they have to be dead on. If not quartered on the Berkshire, though, the side rods may wear faster, & wear "ovaled" out.
In this repair case, if the wheels do come off(the two back axles would be involved), it's best & easiest to keep them quartered and to carefully note which position they were in for reassembly. The splines will re-align when you get close to their original positions on the axles.
To make sure your wheels are quartered correctly, lay the assembly, wheel sides down on a copier machine and make a copy of each set (sides) of wheels. Copy both sides before disassembling. This will show you exactly how the wheel should go when it's re-installed.
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