RE: Lionel Visionline Challenger Driver Sync -> I intend to make them out of SYNC.

it’s easy to do.  search youtube someone made a video of doing it i believe on a H7.   same principle.   i like them in synced visually. i’m for sure the odd man out here 

You just have to remove the shoulder screw for the front set of drivers and slide them forward enough to disengage the drive shaft coupling.  Rotate it a quarter turn and then slide it back together, put the screw back in.

Just curious, if you do the mechanical shift the chuffs are always out of sync. If you send it to Lionel for a new sound set do the chuffs go in and out of sync like my 20 year old MTH Challenger?

Pete

Pete, unless your MTH Challenger is the Railking with two motors, I can't imagine how the physical drivers go in and out of sync, they're geared together!  There's nothing in any of the single motored articulated locomotives that can create the actual drivers drifting in and out of synchronization like the real thing. 

The audio is a different matter, the shipment back to Lionel is specifically to fix the sound set so you get the drifting in and out of sync sounds.  The older Lionel locomotives already have that.

The MTH drivers don't go out of sync but the chuff sound does go in and out of sync.

Pete

OK, we're in agreement there.   Lionel sounds do that as well, it was just the new VL Challenger that they screwed up.

It is probably too expensive for retrofit, but I have a single motor Mallet that goes in & out of synch.  Takes a different gear ratio - in my case, 24:1 and 25:1.

The action is periodic, but even if you know beforehand what I did, you cannot see it.  Doesn't seem to affect pulling power.

Probably decreases the life of the traction tires a bit.