Hi all,

I'd better add, that this method of re-securing the BigBoy to it's base, involves you being able to use both hands at the same time, one hand to balance/locate the base over the edge of the table and then the other to position and tighten the screw.

So, that will be everyone using the "upside down" method then.

No seriously, it is very easy to do and with no damage to the Loco, with it pressing against any foam etc, while upside down.

Ian.

Thanks for the reply
That could be the mystery, or it could be as simple as, the ones with a loose screw was made on a Friday afternoon before a holiday weekend.

As for putting the Big Boy back on the base, I did it the way David mentioned in the 1st post of this thread, upside down on its foam packing, I thought it was quite simple.
Ian, your method sounds good also, just don't pull it to far over the edge
(That would be a sad day for sure)

They are nice but I do not want one. Just too Big.

Same as me.
I do love these models .
But they couldn't run on my layout .
therefore, it's always a big pleasure to watch them on others layouts.

Regards
Joël

Hi Ian, why not, why not...
But don't tempt me to find one .
First, Bigboy is not SNCF, I promised this year to focus on it to fit to my layout scenery...
Second, sure BigBoy will look great on my 3 meters long straight track - I've forgotten...
But Märklin models need to RUN and Bigboy needs to pull at least a hundred of boxcars
to strongly climb the Sherman Hill...
Third, if somebody gives me one I won't refuse her

Regards
Joël

Hi Joel,
Yes, why not is what I thought

Thanks for the link to the great pic of 4017 on Sherman Hill

Hi all,
Slightly off-topic,.....Athearn has announced a Big Boy and Challenger.

See: http://www.athearn.com/Articles/Hobbywire.aspx

Dr D

Hello all,

First of all, I would like to thank David (Klarinettenmeister) again for opening this interesting and helpful thread, and for his kind assistance through the process of fixing the problem with the "mysterious" screw on my 37994. Also, many thanks to GTSE800.

I would like to share with you some of the pictures that I took of the loco entrails during the process, and some other information that I've been able to collect.

Because it is in my nature not to leave any stone unturned (I'm a scheduler by trade!), I wrote an email to both the Märklin Kundendienst in Germany and to kind Miss Brenda at Walthers. Miss Brenda was able to get the part number for me (the mysterious screw, which does not appear on the locomotive's part drawings). The part number is: E753000 (old number 753000), in case yours needs to be ordered. However neither Märklin.de nor Walthers technical departments (the former never answered and the latter got the part number for me) seemed to have a clue about why the screw was "found" rattling about in the box. The latter believed it was placed there by mistake, i.e., an "extra", bonus screw may have been put on the Lok. And then some! As it turns out, this screw holds in place the front carriage of the locomotive, which otherwise may shift apart while the cardan rod will get dislodge during the process and the front wheels will simply stop running on you. Lovely!

Some background information: from what I have been able to read, the issue with the "mystery" screw seems to date back to the early 37990 (34990) BB. I only learned about this screw when I found it rattling about in the box of my 37992. Since I had to send that loco back to the factory for getting the sound speaker repaired (which melted during the warranty period), I asked the then Ken Brzenk to also solve the problem with the screw. However, he never told me where the screw would go. I remember checking in vain the part drawings of my 37990 to try to find it. I still have to check now my 37990 and 37993 to see if the screw is to be found in the box, or if it is still sitting loose inside the loco. Conclusion: the screw is a recurring problem and, despite Märklin having sold at least six versions of BBs or so, it is still not shown in the part drawings!

My friend Eduardo, on this forum, has a theory: the nice, long-nailed ladies at the Märklin factory may need, for some technical reason, to loosen the screw, or not to screw it all the way in, during the assembly process of the chassis, and then totally forget to fasten it good on some of the BBs. It seems a logical theory to me, and I'm willing to endorse it.

Now, how come, after 13 years' or so of manufacturing BB, Märklin.de do not have a clue of why it is found loose in the box? Only the gods know. And why haven't they taken the pains to correct the drawings on this $900 Lok for us mortals to understand? I might never know. Maybe one of our honorable German-speaking members on this forum would like to convey this request -auf Deutsch- to Märklin.de. They might listen. (Maybe Herr Lutz is sneak-reading this post and he may follow suit.)

Here's what I did. The loco doesn't need to be fixed to its wooden base. I removed first the caps that hide the screws that hold the locomotive's upper body (boiler). The larger cap is a bit tricky. I carefully used an X-acto knife to pop loose the cap. In order to locate the hole where the screw goes, please look first at the following picture (courtesy of Klarinettenmeister):




There are two screws that need to be removed in order to lift the circuit card and get to the right spot. One of the screws is on top of the green card (to the right) and the other screw is on the left, right in the middle of the copper contacts for the smoke generators. Lift the card carefully in order not to disengage any of the soldered cables.

Once this is done, the spot can be found easily just below the cardan rod and white cup:



You'll need plenty of light, a magnetized small flat screwdriver, and possibly a lamp with a magnifying glass (if you are like me). Once you've positioned the screw vertically in the hole by lifting it with the magnetized screwdriver (you may need to move the front carriage of the locomotive slightly back and forward for the screw to find its right way in), fasten the screw by means of the small screwdriver which you will have to insert sideways into the screw's slot and turn at 90 or 180 degrees at a time until you've completely fastened the screw. Be careful not to damage or dislodge the cardan rod from the white cup. Be patient!

Here's the screw finally fastened in place. Now you can put the boiler back on and fix the screws and caps.



That should take care of it. Now I'm able to enjoy my 37994 exactly like it was meant to be.

Good luck!

Hi Ian & Glen,
Thanks for sharing your beatiful models !

I've tried and tried to upload the smallest possible wmv file
to show you a small BigBoy movie but even if the file was
really smaller than the 19531Kb accepted, there was still errors of size .


So hereafter, Just a few pics of the movie.
Sorry again.


Regards
Joël

The 753000 screw is a very common spare part.You can see the booklets of 37490,39050,37030,39010,39011 etc.I lost the front screw of my 39050 after a long ride to a very large layout.When the ride finished i picked up the loco to put on the box and the frond boggie with the four little wheels staying on the trucks.Then it was difficult to find the screw in such a large layout and i bought five spare parts.I believe that is a necessary spare part because it is common to a lot of locos.

WOW - congratulations on your brand new beauties, Gentlemen !!!

Hi Bryan!

Could you show what part on a picture? Have you looked for it on the exploded view?

Hi Michael,

Welcome to the forum.

Ian.

Hi Ian

Thank`s

Michael

I just checked the Parts listings for 05.001 (37050) It has a different part number for the Front bogie screw #753540 which is showing as AVAILABLE
It could be different altogether, but it maybe, that it is just a bit shorter, and a better temporary replacement than the top body screw that Michael has used, to secure the front truck of his Big Boy. It is at least a cylinder screw and most likely a different length only.
In due corse I will check my 050.003 and 05.001 out, and compare the screws and report back in case somebody needs a new one urgently

Hi Michael, I got my 37050 out the other day, just need to get the 39050 and compare the front truck screws which I'll do in the coming days. Whilst browsing my pics for another topic i found this one

It is a 37990 being admired lustfully by list member Rick (kariosls37) on the Palmerston North Club's layout at the Euro Mini Convention there last year at Easter

Hi All, Michael
Hope you all had a very merry Xmas and have a Happy New Year

Sorry, I haven't given much time to MRR or the forum over the last four months or so. However with some time over the holidays I was browsing ebay and found this; http://www.ebay.com/itm/...&hash=item35c1a5de95

I hope the link works for you all that need the screw. Eckert Engineering carry a lot of small Marklin Parts. There is a chart of the Shouldered screws and their dimensions and numbers on the listing. It's worth browsing their sit or doing a search for a particular part to amortise the postage. I have bought a few items from them over the years and the service and the item have been first class. The best thing is you can buy one screw not 20

I'll still pull apart my '05 Loks, over the holidays when I get the chance just to compare the screws between models and their P/Ns and see if they are a solution.

See page 51 of Big boy manual if you already have it. Part number 206370.

I watch some 37994 running on youtube and it is very good smooth running, Most Big Boy are 5 poles.

The reason = Cost Reduction !
Mr Pluta has spearheaded a campaign to reduce costs: it is to him that we owe the generalization of 3-pole motors on Marklin models! (confirmed from good source in Göppingen)
Reduce, reduce, reduce again... until you cannot put the name "MARKLIN" on it : here was the limit not to be exceeded
in the poll You should have added a question: Would you buy a Big Boy with a 3-pole motor ?
(my answer : certainly not ! I cannot imagine such a nice model with poor motorization)

Edited by user 24 March 2014 12:20:21(UTC)  | Reason: Not specified

I don't have a Marklin Bigboy but I do have an O guage MTH rail king big boy. It isn't full scal but is still huge. As for it's pulling power lets just say it will pull a train longer then the amount of track I have.

Hi All:
I have a Big Boy but I don't have the big layout, so I play my Big Boy by this way.

dynamic roller demo stand:


roller test stand:


Two kind of roller stand made by RailStand, more detail & pictures & videos please visit www.trains.com.tw/railstand.asp

Edited by user 20 March 2015 14:52:02(UTC)  | Reason: Not specified

Yes, I think you can David.

Added to the poll options.

I won an auction before a few days, so i add my self to the poll off the Big Boy owners.After reading all the above posts my choise was the 37993 version of the beast.It is impossible to run the locomotive to my layout because of the catenary system ,so i have to wait to run her to another bigger layout.Never mind,i think this loco is a must have for a USA trains collector if he can afford the price tag.I am huppy with my choise.