Check out http://www.srha.net/   Southern Railway Historical Association

An example: https://www.amazon.com/HanTof-800pcs-Kinds-Screws-Assortment/dp/B07HLJ97J6

Years ago, I used to double head a Mantua/Tyco 2-8-2 and 2-8-0 all night long at the club layout at the UIUC.  They both had the original open frame motors, and totally stock drive trains.  The club had more than adequate power supply, but a previous club member (graduated long before and gone) had used 24 ga. telephone wire for power runs.  20 feet from the power supply, on the steep grade, they would stall out while drawing 1½ amps*.  Just too much resistance in the circuit.  The layout was DC block control - long before DCC came about.

Moral: make sure that you have adequate power, and adequate wiring to support the current loads required by the locomotives.  For DC operation, a voltmeter and ammeter are practically required.

* One locomotive would make the grade by itself, drawing an amp to do it.

You can get an assortment of miniature screws from Amazon and other sources, and try until you find the correct thread size.  The screw sets are for eyeglasses, laptops and phones.

Definitely agree it will be easier to just purchase a new locomotive.

A major thing you have against finding the correct drivers is that you have to know the exact model of the GS4 you are looking for, there have been at least two that I know of, and possibly more.  And the drivers are not interchangeable.

All the calls for a specific model are well and good.

But you need to show a business case for the return on investment.  It takes $100K+ for the research if there is an existing example to measure, and far more if there is not - identifying where one exists in a museum is helpfully, $100K to $250K for the tooling, $50K to $100K for parts and assembly, $5K to $10K per container shipping cost to the warehouse, etc, etc.  Easily a half million dollars tied up before the first sale.

If you can demonstrate to Bachmann or one of the other companies in the business that they will make a profit on the deal, and you are willing to put up some form of insurance, things can get done.  Working the with the appropriate historical society is also beneficial.

Quote from: Trainman203 on February 03, 2019, 10:53:05 PM
Yes, but whose got all those old issues ....

The DVD is a lot easier to get the old issue information from, no paper to deal with, and it is indexed....

Quote from: brokenrail on May 20, 2016, 08:24:16 PM
Bachmanns railings that are on their gp 50 will not work.The gp 38-2 are the closest to the prototype Bachmann has that are very accurate compared to the other 2.The 50's railings are 1 long Stanton too long to fit the gp 40 correctly on the blower housing side and walkway step that does not fit the 50 correctly either.Smokey Valley makes metal rail kits for Bachmann diesels also.If a rail kit can be found for a older Atlas/Concore GP 40 shell.They can be used as a direct fit for the Bachmann gp 40 shell since they are of the same tooling. If you compair the 2 they are practically identical except for the later Bachmann version that filled the mold on grab irons in the tooling to have no molded grab irons at all unless you add them yourself. The very old pancake gp 40's shells are different all together and must have been discontinued when the old Atlas tooling showed up.Abit of history of the 40 for you.
Johnny

A bit more history; the original Atlas GP40 was made by Roco in Austria for Atlas in the 1980s.  After Atlas dropped the GP40 (and GP38, GP38HH, SD24 & SD35 all made by Roco) model - shortly after Atlas contracted with Kato for the RS3, Concor picked up the Roco tooling and moved it first to Mexico, and then to China.  Bachmann's original GP40 was in production at the same time as the Atlas model made by Roco, and sold for less than  half the price. 

Some resources:

http://cs.trains.com/mrr/f/88/t/228181.aspx
http://hoseeker.net/assemblyexplosionbachmann/bachmannk4spectrum462.jpg

There have been several versions of the Spectrum K4 over the decades - the first ones from the early 1990's had a horizontally split frame, with each have of the frame connected to one  rail.  Later Bachmann went to a different design with a single main frame.  Not many parts interchange.

Nigel

The longer draw bar allows the engine - tender combination to go around tighter radius curves.

1/8" hole is way too big.  Think along the lines of 1mm (.040") diameter hole.

Or you do the easy thing, and purchase a Peco one:
http://www.traintimehobby.com/products/Peco-HO-Code-83-Inspection-Pit-%252d-8356.html

The Bachmann Plus F7 models are excellent - and it has been 15 years or more since they were sold new.  They are heavy, have big motors and a solid metal chassis that practically fills the shell.  Decoder installation is not for the faint of heart, nor inexperienced.  For sound, I would add a dummy B unit in the middle of the consist; you might be able to wire in a couple tiny speakers into the powered units, with a couple of big speakers in the dummy.  Without milling the chassis of the Plus models, that is about all you can do.

On DC, the Plus F7 models are great - better than today's light weights.

Hi Joe;

This is Bachmann's USA website, they also have a UK website, where you can probably find better answers to your questions.  http://www.bachmann.co.uk/support.php

In the USA, we try to match the locomotive number with a prototype number, and detail the model to match the real thing.  Most higher quality models in the USA are available with and without numbers for that purpose.

Hi;

Bachmann's OO train models, available in the UK have couplers compatible with other manufacturers such as Hornby's offering.

Bachmann's HO train models have a different style of couplers, which are compatible with the USA standard Kadee and other couplers.

This is Bachmann's USA website, they also have a UK website, where you can probably find better answers to your questions.