# lionel skipping



## blumule (Jan 2, 2010)

Hi, im new to model railroading and have met my first dilemna. I have been given a lionel diesel g scale. I think its a gp 40 or 90 not sure. It says union pacific. My problem is it skips or jerks like theres a short in it . The track is brand new usa brass , very very clean so thats not the problem. I have cleaned the wheels numerous times. If i touch the wires straight to the wheels it runs pretty as you please , no stalling, or hesitation at all. But as soon as i lay it on track it just sputters and spits. This is the reason it was given to me.Hate to trash it , it seems like a quality heavy engine.Any tips would be appreciated.


----------



## George Schreyer (Jan 16, 2009)

Brass wheels? If so, clean them. Flip it over, connect some power somewhere to make the motor run, burnish the wheels with a Dremel tool and a brass wire wheel.


----------



## blumule (Jan 2, 2010)

i dont think brass . looks like regular metal.


----------



## Greg Elmassian (Jan 3, 2008)

Sounds like you have to disassemble it to check for broken or fractured wires... 

Regards, Greg


----------



## George Schreyer (Jan 16, 2009)

they made a GP20 about 20 years ago. It had four motors. A spotting feature is that the pilots on both ends are attached to the trucks so that they pivot. 

Lionel has used lots of brass wheels, all cause problems. They may have used something else on the GP20, but clean them anyway. Also check each pair of wheels to make sure that each pair is picking up power. Slop each wheel set side to side to see that it picks up power at the extremes of the wheels slop. If you find that contact is lost with wheel slop, suspect bad brush springs. Pull the questionable ones out, all should be bright silver. If they have a hint of brown, they are toast. 

Also check that pickup is retained as you rotate the trucks by hand.


----------



## Randy Stone (Jan 2, 2008)

Does this loco use the same type spring loaded brushed to transmit the power from the wheels to the motor as the 060 Lionel Steam loco? If so, the back of the wheels need cleaned and the brushes, springs and the cylinder they are in all need cleaned. Upside down with no load the motor runs fine because there is no load. When put on the track, the extra load of the weight of the loco pulls more amps than the dirty brush, wheels, springs and cyclinders will allow.


----------



## George Schreyer (Jan 16, 2009)

does the thing run somewhat smoothly for a few seconds and THEN start to stutter? 

If so, REALLY suspect the springs. That loco can draw lots of current and if the springs heat, they loose spring force and the wheel pickups go bad.


----------



## blumule (Jan 2, 2010)

this is the one.Ill try to clean and check the springs.


----------



## blumule (Jan 2, 2010)

Thanks. Ill try that.Sounds logical


----------



## blumule (Jan 2, 2010)

ill give all these a try.This is the lionel with 4 mtors.It runs very smooth upside down.I replaced the springs and contacts on several of the wheels but not all.I coated the back of the wheels with a dialectic grease, very thin coat .im suspecting this was not a very good idea.Also there was a couple of springs that were slightly brown i didnt replace.Ill go back in and let you know what i find.


----------



## Randy Stone (Jan 2, 2008)

You need to clean the grease off the back of the wheels and the brushes for sure.


----------



## George Schreyer (Jan 16, 2009)

one easy way to check the springs is to insert a knife blade between the contact piston and the wheel and press it back into the truck. When released, it should snap back to the wheel smartly. If not, the spring is toast. 

Try them all, you'll get a feel for the good ones and the bad ones.... unless they are ALL bad.


----------



## BarrysBigTrains (Sep 4, 2008)

George is on the right track. One other observation, if the current goes through the brush/plunger then THRU the spring, this will be a contiuous problem.

The plunger-spring assemblies can be replaced with my brass tube, spring, and plunger. This way the current runs through the tube and not through the spring.

Let me know if I can help.

Barry - BBT 


PS: dialectric grease is an insulator, not a conductor.


----------



## blumule (Jan 2, 2010)

i like the idea of a brass tube. Why didnt lionel think of it ?.Any way i will clean and check spring rebound later today. thanks for the ideas.


----------



## blumule (Jan 2, 2010)

cleaned and checked the brushes and springs .The springs all seemed to have good rebound to them plus theher brass and its hard to tell if theyer burnt.I put a meter on them and the continuity seems good.As usual it runs great upside down but on the track its ugh ugh ugh as if theres ashort.Its blowing my mind.I guess it blew my buddys mind enough to give it away.i checked all wires but thers so many diodes and capacitors and circuit boards ill never figure it out.It still makes a nice display this thing is heavy.


----------



## Stan Cedarleaf (Jan 2, 2008)

What type of power supply are you using?? Could it possibly be that your power supply does not have enough amperage? 

I've had the same thing happen with an under powered "transformer".


----------



## blumule (Jan 2, 2010)

im testing it on a 4 x 4 foot solid brass track with a USA M40 transformer. Should be sufficient. It pushes my other trains.I think there is probably a glitch in the wiring. Its fun upside down listening to the diesel scream and the wheels churning.


----------



## George Schreyer (Jan 16, 2009)

BTW, the private message system on this site doesn't work very well. I got your message but could not reply to it. Use regular email 

it sounds like the Lionel is overloading your power packs. Drop another engine on the track at the same time, it will probably cut out at the same time. 

The Lionel GP20 draws a lot of current and you might need more smoke to run it. Even a 6200 has limited power output.


----------



## blumule (Jan 2, 2010)

thanks george u might very well be right. Never even thought of that. Im learning more as i go . well at least i can run it at half throttle. thanks again.


----------

