Nominations for the most frustrating locomotive mechansim you've worked on

[Jimbo]

Lifelike old time 040.

???
Did Life Like do ANY 0-4-0 in N scale?

[pdx1955]

Con-cor C636's - terrible geartrain with worms and gears that don't stay meshed . Probably the worst of all that that I had during that period.

[basementcalling]

The original Kato GP38-2s were, well, unique, to put it politely.  Then Kato got the mechanisms perfected for future engines.

[Dwight in Toronto]

Bachmann’s PCC streetcar from, oh, maybe 15 years ago (?).  For me, total running time was perhaps an hour or so, over a measly 2 week span, and then the plastic gear train went for a crap.

I documented the restoration of this thing on TRW a couple months ago using a TomyTec chassis, and added dcc, led’s and details such as windshield wipers, backlit destination board, rope retractor etc.  After all those years, “it lives” once again!

[randgust]

The original Kato GP38-2s were, well, unique, to put it politely.  Then Kato got the mechanisms perfected for future engines.

I like that "unique".   They meet my ideal criteria, looked great, pulled like mules, absolutely impossible to work on and one of the most erratic electrical pickups of all time.   No explanation for that chassis design.   If you never tangled with this thing see:  http://www.spookshow.net/loco/katogp38.html

I still have one in service because it wildly outpulls the Atlas GP38 3:1, no kidding.  It's ridiculous, its the highest tractive effort diesel I own and makes the Atlas GP38 inexplicably wimpy.  But on ANY kind of cross level or a insulated frog,  stalling.  I set up removable .010 'jumper cables' so I can cross-plug the contacts against a companion Atlas Kato GP30 like a slug unit, and the pair of them are now just unstoppable.   And if you can get past that pickup problem, it's just a wonderful locomotive.   But I spent YEARS trying to fix it with jury-rigged brass springs, wipers, you name it.   Nothing worked.   I still have another one as a parts donor but haven't needed it.

Yes, nominated as the 'best running locomotive made in N scale' yet enough to make you absolutely crazy working on it. I'd about forgotten about that one but I'll second the motion to nominate it.   And however crazy it is, still gets an "A" from Mark.