Help with the GP7

Did the gear problem keep it from running?  If so, maybe the motor drivers have taken a hit; or the reader is not working.  The runaway is usually a problem with the reader; the 85206 comes up as a Legacy PRR F7.  Sounds silly but do a smell test on the motherboard.  Falcon

It is a Legacy GP-7 8512  SKU# 6-28573  sorry for the mistaken numbers.

Yes- the engine was the second in the lashup when it locked up.  Though the time was brief when I attempted to see what happened (not knowing that it was a mechanical issue in the gears) I did apply power to it before taking it off the track.

IF the board is fried, which one?  And how do I fix it?  I would hate to write off the entire thing!!

I am a bit of a do-it-yourself, just don't think I am up to a total replacement of a motherboard!!  

I had the NYC GP7 from the same run.

Mine began erratic accelerating and I discovered that the flywheel with the speed control encoder ring was loose on the motor shaft.

I snuggled up the set screw on the flywheel and it never happened again.

This may not be your issue,but it's worth a shot.

Before you open up the GP 7, test your track and connections.  Does the GP 9 behave similarly or just the GP 7? 

I had a situation where the internal fuse in the wall wart for my Cab 1L blew and 18 volts was sent to the tracks  & loss of command signal.  My TMCC NW2 sped off uncontrolled through a bumper and took a swan dive to the floor from 45 inches. 

If it's the fuse  then it's an easy fix. 

FWIW, a few years ago I bought one of these early Legacy GP-7 engines with the same issue, I had to replace the DCDS and all was well.  Uncontrolled speed as soon as you crack the throttle indicates you have an issue with the speed control, so you need to check the flywheel, encoder, wiring to the DCDS, and the DCDS.

Would not hurt to open it up and check the flywheel; turn the flywheel while holding the wheels and see if it turns freely; hopefully it is held with a hex screw; if no hex and loose put a drop of CA on the shaft.  If not the flywheel, check the continuity/connectors to the motherboard (have encountered a broken wire on a crimp) to the motor board.  Look at mother board closely or take a smell; usually an indicator; good luck; Falcon

The flywheel on this one has a set screw.

As I was looking around the flywheel came OFF.  It has been loose and spinning.  A post I found from GRJ that HE also had one with a loose flywheel keyed me.So at least two issues of QC- first a dry gear shaft, and then a loose flywheel.  Not having a proper allen wrench- I used a drill bit by hand and tightened it.   Then a drop of CA.

SO- what size wrench should I buy for future use??

Thanks guys- the OGR Forum strikes again!!  

Mike

John may know the exact size. I used one of the smaller metric Allen keys on my old craftsman set.

Looking at it it had to be either the 1.5, 2.0 , or 2.5 mm wrenches. If that at least helps narrow it down.

Note to newbie readers of this thread: You might need a bit of a tech BG to take on these kinds of issues that GRJohn and others do (and huge thanks for those who contribute advanced knowledge to benefit all of us).

However, it needs to be said that paying several hundred bucks for an engine that you have to immediately run tests on and lean on others for help to fix is a travesty. This is only one reason some of us still lean on good ol' conventional running. If, or when, those locos start acting up, most people can fix them by using well-known techniques including the purchase of a good $25 Greenberg repair book. 

The other big issue here IMHO is the fact that when I run, repair, maintain, paint or scenic trains and layout, or simply enjoy looking at my trains, my Imagination is at full play. I've watched train runners at meets and online vids, and I see (mostly) guys wired & tethered to their remotes. It sure seems to reign in imagination. 

Virginian, even conventional locos have flywheels.  It's actually a good thing that the flywheel was held on by a set screw, because it makes servicing easier. 

That being said, I agree with you about the lack of quality control.  I wouldn't mind if Lionel sold the loco as a basic kit that you put together yourself (screwdriver and soldering iron assembly.)  Then, you could decide if you wanted to add sound, command control, etc., accepting the potential trade-offs in reliability.

As part of the OGR Continuing Education Program, I will point out that there are no dashes in EMD model numbers. The engines under discussion here are a GP7 and a GP9, with no dashes.

The only place where EMD used dashes in a model number was in their “Dash Two” model lineup, as in SD40-2, GP40-2, etc.

Here endeth the lesson...  

Mike, glad you got it fixed; and you fixed it; and with a drill bit!  Have fun; Falcon

@RickO posted:

John may know the exact size. I used one of the smaller metric Allen keys on my old craftsman set.

Looking at it it had to be either the 1.5, 2.0 , or 2.5 mm wrenches. If that at least helps narrow it down.

Too tell the truth, I just have a set of metric and SAE hex bits, and I just stuff them in until I get the right fit.  I don't recall the exact size, other than it's very small.

The OP indicated that this train was NOS - meaning new (never run) old stock, that he was able to purchase; presumably at a very good price. This loco was manufactured around 2008, which means it could have been sitting on a shelf or in storage for approximately 12 years with no usage before the OP purchased it and attempted to run it.

I think it's patently unfair to criticize either the manufacturer or the type of control system used for anything that occurred under these kinds of circumstances. Lord knows how one of us would perform after sitting on a shelf for over a decade. 

Sorry- I disagree.  Maybe "crispy" grease and/or dried-out traction tires.  But a  dry gear shaft is NOT caused by evaporation and set screws do not loosen on their own. It's caused by a manufacturer's sloppy execution of Lionel's plans.  

To be fair- I love these locomotives!  I have two of the same number.  The GP7s LOOK great (although I am no rivet-counter) but they just look good to me.  This generation (I think the first of the Legacies) had some great features, such as crew talk that references the specific road number, and sound  that is much more realistic to me than the later ones. 

The set-screw mounted flywheels on the GP9s  are a good thing- better than factory-pressed on flywheels that cannot be removed for a motor change.  To compare 2008 to ten years later- I also have the 2018 F7  A/A set, which I bought brand new through a LHS.  

Sorry - I disagree.

Grease and lube do dry out - that's why we oil and lubricate our trains on a regular schedule. If you think the ring and pinion gears in the rear end of a '57 Plymouth are going to be perfectly lubed after twenty years of storage ... well, good luck with that.

And set screws do loosen up - that's why they make threadlocker.

We can reserve the right to disagree, but I just don't think it's fair to the manufacturer to take a locomotive that's been sitting in storage for 12 years and expect that it's going to run as perfect as the day it left the factory.

WOW guys, back to your neutral corners, the fight's over.

Hah - no fight - just a good natured difference of opinion ....

Woweeee! O.k.John . Good advice.I'm back to my corner.

I'm just glad Mike was able to fix his gp7.