[lovguitar]

Hello -- I bought a 736 off ebay and while it is cosmetically very nice, it has never run properly. It starts off fine but within maybe 30 seconds it begins to make a kind of grinding sound and shudders. Shortly after that, it stops. It will run backwards a few inches and stop again, then will run forward a few inches and stop. It basically locks up. I have opened it up and:1. removed old lubricant from worm gear area and re-lubed with automobile 5w30 oil; 2. Cleaned armature and replaced brushes; 3. lubricated all axles and moving parts, very carefully and with just a tiny bit of oil; 4. ordered shims for the engine and carefully put them into place and run the motor on a stand.

Despite all of the above, the problem continues. Finally, I have tried removing all of the drive rods and running the engine with just the rear set of wheels. Then it runs perfectly - no funny noises, no stalling, even when I put resistance on the driving wheels.

When the drive rods are put back, it starts the same thing. I have compared the position of the wheels and the placement of all the parts with a working 736 and everything is the same, except mine doesn't run.

I'm running out of ideas. Any thoughts on this? All help much appreciated!

Paul

 

[teledoc]

When you removed the drive rods, it ran perfectly, with no binding, indicates you have a problem with the “Quartering” of the wheels. You can try putting just one drive rod on, and see how it runs. Reverse the drive rod to opposite side, and that should indicate which side is out of Quartering. It’s possible the previous owner removed the wheels, (for whatever reason), and didn’t get the Quartering correct. Also check to see if you have excessive play on each set of axles, with the rods off. That would tell you you have a seriously worn bushing. It’s a matter of ‘process of elimination’. That’s my suggestion.

 

[sjm9911]

It has to do with the rods, since it works without them. Check to see if there binding on something. Turn the wheels by hand to see if they catch something.

 

[tjcruiser]

I'll expand on Doc's comments a bit...

You need to check the "quartering" of the drive rods, but let me elaborate on what that means:

1) On one side of the loco, the screws/studs that hold a drive rod must be lined up EXACTLY with each other. I.e., if one wheel has stud/screw oriented upward at 12:00, then the mating wheels on that side of the loco must also be exactly at 12:00. I suspect yours is not ... you likely have some misalignment to the rotational orientation.

2) Then, with item (1) checked on both sides of the loco, we then get into true "quartering", meaning that if the left side of the loco's wheels are positioned at 12:00, then the right side of the loco's wheels are positioned at specifically 3:00 or 9:00 ... not anywhere else. On real steam locos, this was done so that the thrust of the drive rod (from the steam piston) on one side of the loco would then be followed in an efficient manner from the thrust on the other side of the loco. On electric model trains, this is less critical, as the internal motor is really powering the wheels, and the drive rods are simply going along for the ride.

So, most critical is (1), above. Check that.

Regards,

TJ

 

[Dano]

736 is driven only by one axle so the all running gear alignment and lubrication is critical.

 

[santafe158]

As Dano mentioned, the 736 is driven only by the rear axle. Similarly to a real steam locomotive where the main rod is only connected to one drive wheel set, the side rods do transmit some of the power from that rear axle to the axles ahead of it. I've heard that if the screw holes in the rods get worn oblong from a lack of lubrication, symptoms as you describe above could occur.

 

[teledoc]

What Dano & santafe158 posted is correct with the rear most axle is the only driven axle. The proper Quartering of the 736 is like the S-2 Turbines, which is a 6-8-6 arrangement. The right side rods, if positioned at 12:00 o’clock(think of a clock face), should have the left side rods at the 9:00 o’clock position. The left side runs 90 degrees ahead of the right side. As mentioned, check the holes in the long side rod, to see if any are enlarged, or elongated. That could cause binding as you describe. Even one axle set could be just enough out of quarter, to also cause binding.

Other steam engines have opposite Quartering, where the right side leads the left by 90 degrees.

 

[lovguitar]

Yes -- you are right on target. The quartering is off. When one set point at 12 o'clock, two wheels on the other side are slightly off 3 o'clock. I'm going to either have to buy a wheel puller and carefully work this or bring/send it to someone more advanced than I am!

Thanks for your help!

 

[lovguitar]

Thank you for your reply. This is exactly the issue. I need to quarter the wheels!

 

[lovguitar]

Thank you for your reply. I reached the same conclusion but haven't been able to resolve the problems. The rods themselves look OK but the quartering of the wheels is a little off. Drat!!

 

[teledoc]

I can suggest a substitute wheel puller. HD or Lowe’s sell a faucet puller which is what Olsen’s Toy TrainParts sells. The center pin is the same size as the Postwar axles, and with a little grinding of the claw tabs,it should fit beneath the wheel. You didn’t say which wheels were off Quarter, such as the center two sets, or other combo. Pulling the wheels is easy part, but the pressing back on is tricky. Best suggestion is try and find someone who has a wheel press, with the correct wheel cups, to make it correct.

 

[lovguitar]

lionel 736 Quartering

I can suggest a substitute wheel puller. HD or Lowe’s sell a faucet puller which is what Olsen’s Toy TrainParts sells. The center pin is the same size as the Postwar axles, and with a little grinding of the claw tabs,it should fit beneath the wheel. You didn’t say which wheels were off Quarter, such as the center two sets, or other combo. Pulling the wheels is easy part, but the pressing back on is tricky. Best suggestion is try and find someone who has a wheel press, with the correct wheel cups, to make it correct.

Thank you for your suggestion. I'll try to find someone local who has a wheel press with the correct cups!