Hi Carlos

It is very difficult to answer your question. The reason is many Märklin locos made with Large (LFCM) or Small Flat Collector (SFCM) were converted around 1970-1980 to drum collector (DCM)
So the manufacturing date is more important than the model number. Example: my present 3038 loco has a DCM with early brush holder in translucent nylon while my previous 3038 was with a SFCM and raised numbers. So the model number in many cases does not give a clue.
Most models designed after 1980 have DCM
Cheers

Jean

PS In case you are interested in the various Märklin motor types, please check this https://www.stayathome.ch/motoren.htm

Thank you all.
Yes, it looks like the only way is to open them up
Thanks!

And even then, after opening up the loco and confirming a DCM motor is onboard, it can still be deceiving ... ...
Years ago I had converted my old SBB Ce 6/8 Brown Crok (3352) with a 6080 decoder. It certainly had a DCM motor :





The loco is the "younger sibling" of my older, traditional 3015 (OO) :





Yesterday I converted my 3352 further with an ESU LokPilot 4.0, also with a view to upgrading the motor to 5 pole with a 60941 kit.

Actually fitting the 60941 went fine with plenty of static breadth clearance within the body of the central unit of the Crok, but on trial
running it derailed, however only on 2221 bends. I'm sure we are all aware that the 5 pole armature is a bit longer than the 3 pole
and so the kit's permanent magnet is actually thicker than the original electromagnet piece it replaces, hence the conversion makes
the motor a bit wider (on the motorshield side) - in this case just enough to curtail the combined excursion of the rear upon the
central unit of the Crok on that side but only when moving rear-end-first (?make sense?) which was when the motershield side
imposed upon the inner surface of the central body. Not suitable to fix with some material parring.

In the past I had experienced similar problems in upgrading to 5 pole the motor on another "Crocodile", my DB BR 194 (3322),
(the "German Crocodile") which I resolved by filing a little off one spot of the central body to free up the movement :





After discussions re other conversions with RayF some time ago, I have kept on hand the ESU magnets
for the three motor types to provide for such situations. The ESU magnets are the same width as the original electromagnet
units. In this case of the 3352 I changed the conversion back to the original motorshield and 3 pole armature incorporating
an ESU magnet - this gave full excursion of the articulated body movement and no more derailing. (Thanks Ray !!)

In the past I have been keen to "upgrade" my motors to 5 pole upon decoder upgrade and have usually been successful,
albeit at times needing some "workaround"; this is the first time I have been unable to do so, and thus needed to use the
ESU magnet. I must say that with the ESU decoder the 3352 motor runs fine and I really cannot see a discernable
difference to the running of my locos which have 5 pole motors and ESU decoders.
So I would somewhat endorse Dale's previous post #2 at https://www.marklin-user...read-old-locs---new-life
and can understand how some members simply use ESU magnets for all conversions, not bothering with the 5 pole motors.

For the moment I think I will continue to pursue the 5 pole motors when I can, but what an education this has been
and what a great bunch of folk we have on this forum to advise the rest of us !

So, even if you open up to find a DCM motor confirming your information, beware - there can still be problems .

PJ

Thanks again Costas.
Re-viewing your great post I noted that I had seen it all but did not remember what I had read - and only three years ago !

Regards,
Philip

Same goes for some others too, mainly some steam locos from the 80's-90's - brush spring assembly makes contact with the body (electrical ground) - not good at all...

If you have a old analog loc and you want to get it digital. Try out the Marklin 60906 mfx dcc decoder. You donot have to change the engine and you wel get a nice digital loco.
If it drives good analog it will drive digital a little beter even.
You can use this decoder for all the analog locs from Marklin.