GP-9 Slipping with More than 7 Cars

[JTrains]

I recently bought an early 1970s IC #8030 GP-9 off The Bay.  E-Unit’s a little temperamental but I almost always run locked in forward – so no real harm.  Runs smooth as silk on its own or with a small handful of cars.  But, once I get to a consist of about 6 or 7 cars (all MPC or later), it starts slipping when trying to pull cars around curves.  I added some weight to the front half – which allowed me to add another car.  Then, the next car added caused it to revert back to slipping.  The traction tires are new and seem to be holding their grip on the wheels.

I’ve seen some threads that seem to suggest that these aren’t great pullers – but only 7 cars?  I’ve got a similarly-designed 1980ish U36B that can pull about 20 cars around the same track and still has traction to spare.  Is this a lost cause and what I’ve got is essentially a switcher - or - should I be expecting more out of this engine?

[sir james I]

If the cars have needle point axles it should pull more than that. You are correct about the pulling power, a 7 car train was about it. Run the engine long hood forward that puts the motor on the rear, helps some. MPC Lionel sold dummy units for many of their engines, don't buy one as it really adds load to the engine. The MPC engines with six wheel trucks pull much better than their four wheel brothers.

[JTrains]

sir james I

If the cars have needle point axles it should pull more than that. You are correct about the pulling power, a 7 car train was about it. Run the engine long hood forward that puts the motor on the rear, helps some. The MPC engines with six wheel trucks pull much better than their four wheel brothers.

I'm somewhat perplexed on the radical difference in pulling traction between my GP-9 and #8155 Monon U36B.  They are to my eye almost identically constructed (sharing many parts) and I think the GP-9 may even be a bit heavier over the power trucks than the U36B.  Neither has MagneTraction.  Do I just have a Super U36B or is something else in play?

So much for the GP-9's box which says it will pull "over 25 cars"!

sir james I

MPC Lionel sold dummy units for many of their engines, don't buy one as it really adds load to the engine. 

Too funny - one of the cars I use in both GP-9 and U36B consists is a #8156 U36B dummy.  Seems the U36B loves his twin, the GP-9 not so much.

[KRM]

My MPC Boston & Maine GP9 8854 from 1976 is just about maxed pulling the 8855 dummy and 9 cars. With no curve smaller than O34" It could use new Traction tires.

[cwburfle]

Your IC Geep probably needs new traction tires.

[ADCX Rob]

JTrains

So much for the GP-9's box which says it will pull "over 25 cars"!

The 8030 has two hollow roller pickups/collectors on the motor truck. check to see that they are not binding or pushing the truck up off the track.

[fifedog]

If you haven't "tuned" your freight cars, turn them over and add a drop of Labelle light oil at each axle point or housing.  Spin the wheels until they rotatefreely for several seconds.  Might surprise you how much inertia the engine is trying to overcome.

[JTrains]

A random thought: would anyone recommend buying a second GP-9 (since they're only about $50-75 with shipping on The Bay) and then lashing them up to get more total pulling power?  Or would I simply be disappointed by the results X 2?

[rtraincollector]

ADCX Rob

 

 

JTrains

So much for the GP-9's box which says it will pull "over 25 cars"!

 

 

The 8030 has two hollow roller pickups/collectors on the motor truck. check to see that they are not binding or pushing the truck up off the track.

 

Thats another point to add a drop of oil to some say no but have always done so to keep the roller pick-up rolling freely .

2nd engine what I would do first if I was going to go that route would be look for a GP-9 that had magna-traction and if necesary repaint the frame and switch shells. One thing I don't believe asked do you have any grades? anyway if I was going to buy second engine that is way I would go also with a second engine even identical you run into the chance of one running faster/slower than the other putting a strain on the other. on buying the engine with magna-traction just make sure it has same mounting style your engine has.

[sir james I]

Yes adding a second MPC Geep would add greatly to your pulling power. Try it with your U36 and see the difference.

[ADCX Rob]

rtraincollector

Thats another point to add a drop of oil to some say no but have always done so to keep the roller pick-up rolling freely .

I wouldn't do that with this one, there is no roller axle, and trying to oil it would just transfer the lube to the center rail.

[rrlineman]

try this, take the tires off the wheel. rough up the grove surface with a dremel or carboard nail file to break any glaze or polished area's. the tire,if it is slipping, polishes the grove surface.

try for a cross-hatch pattern on the grove around the wheel. using some Walthers Goo, put 4 dots around the wheel and on the tire. wait 2 mins and then re-install the tire. work it flat with a small flat screwdriver or a paint stick. this should increase the pulling about 3 or 4 cars. used to do this all the time when I worked a train store in the 80's and 90's. DO NOT used super glue !!!! Got this Idea from the Lionel guys when they were still in Mt Clemmens. that was how they did it to improve on the pulling  ability of the cheapo GP7's.

 

hope it helps

[servoguy]

I suggest you clean the track in the following way:  Fold up some paper towels to make a pad that you can fasten to a car with rubber bands.  Put some alcohol on the pad and tow it around behind the GP-9.  This will not only clean the track but also clean the wheels on the loco.  I have a post "Fixing Lionel magnetic couplers so they stay closed" with a single motor 2032 pulling a pretty good load.  It has only one motor with magnetraction.  The track was cleaned with paper towels and alcohol.

[JTrains]

So I finally got around to doing some work on this guy - since it seemed to be a weighting problem, I slowly added 1/4 oz. adhesive wheel weights between the motor truck and E-Unit.  At about 10 oz. I started to see a noticeable difference.  I ended up adding 5 more oz. for a total of 15 oz. and can now readily pull 15 or so cars.  Mission accomplished, although I was a bit surprised at how much weight I needed.

One mistake I made was trying to find a way to get some of the weight over the motor truck by adhering some of them to the inside roof of the cab.  I ended up removing them after they created intermittent binding of the wires.  All that is now left of that experiment is 1/2 oz. stuck to the bottom of each side's molded stairs.

[rtraincollector]

V8Vega

 

 

JTrains

A random thought: would anyone recommend buying a second GP-9 (since they're only about $50-75 with shipping on The Bay) and then lashing them up to get more total pulling power?  Or would I simply be disappointed by the results X 2?

 

 

 

 

Thats what I attempt to do with all my MPC era diesels, if for no other reason than because of the plastic gears. Most of my running is display running forward only.

I had a GP-7 MPC that struggled to pull its dummy, I sold it.

 

 That was a big problem and you may have fixed pulling but you may cause a problem with your plastic gears as they were problem-matic to start with. Good news they do make replacement brass gears so if it does happens or maybe someone already has replaced them for you. 

[rtraincollector]

JT sent you a message