3rd Rail Engine Clicking, jerky operation, bad/no speed control

That engine has a taped flywheel. Sounds like the encoder (tach) tape has come loose. If the tape hasn’t shredded itself to pieces, you could glue it back down.

I'll check, thank you - If it is shredded any idea on replacement? Eventually I hope to upgrade the model to PS3, so if the replacement is too difficult or costly for some reason, that may end up my solution.

There might be a pdf of the flywheel stripes you can print out somewhere in the TMCC forum stickie topic. Print it out on sticker paper.

Since it’s an EOB system, you could also disable the cruise and run it like that in the meantime. I can’t remember if this engine used the cam switches for the chuff or the flywheel tape. If the chuffs are messed up, it’s the tape.

Print this at actual size on gummed half-page shipping labels, then just cut out the one you need.

BTW, that was my pal’s Q4b that he brought over to run on my layout sometime last year. When I saw the post, I remembered taking some photos of the mishap and the repair.

Thanks for sharing those photos - they will be helpful when I get the time to work on the Q4b this weekend.