2426 tender uncouples when passing over Scaletrax switches?

Does that have a thumbtack coupler or slider and coils?

Thumbtack can usually be fixed with a layer of plastic tape on the bottom of the thumbtack. (also stops shorts and sparks)

That's because your should be using Lionel 022 switches.

You can try to increase the tension of the contact behind the sliding shoe. The contacts exert less pressure with age and the slide shoe flops around too much going over the switch. As it flops around the little rivet head on the shoe can come in contact with the center rail as it crosses over it. Increasing the pressure of the contact would help keep the shoe more straight. You will have to get at the top side of the mounting plate to get a good angle on the delicate contact. Your results may vary.

Sam, Take a close look as the engine crosses the switch. Some rollers will come in contact with the guard rails. You will then have to insulate that guard rail w/ tape or clear nail polish. But make sure you check that sliding shoe also, the rail is thinner so that sliding shoe may be dropping more onto the rail causing that rivet head to short out on the rail. Hey eddie g, pls don't comment if you have nothing positive to add.

The 022 would give me whiplash running through them - what YOU don't ride in your locomotives?

The 2624 tenders have coil couplers so I figure that something in the way the switch is laid out with current flowing causes the electronic coupler to fire.

I have found that sliding shoe couplers uncouple over atlas and ross switches as well. This is on most equipment with them. The simplest fix I use is to unsolder the wire at the coil coupler and disable it. Put a piece of shrink tube over the wire so that it does not short on anything.

Hey Sam, A 2624 , or a 2426 ? How close is it to a curve? Is the approach through the curve then thru the switch?  That could be your problem. 

Sam,

Just roll the tender slowly through the switch until it activates the coupler and stop.

Then tilt the tender up enough to see where the slide shoe is contacting the center rail. A coupler of coats of clear nail polish there should solve the problem. If you have no problems running trains with the nail polish, then someday you may want to shorten the interfering rail for a permanent fix.

Not only will modern switches fire off the sliding shoe uncoupler they may even knock them off the truck.  To address both issues I use small cable ties.  It takes two. I wrap them around the truck and across the groove in the sliding show.  this elevates them away from the rail which activates them, and puts insulation over the rivet.  By elevating the shoe you also avoid them from getting ripped off by the rail.

Alan

Sam, I use supersnap track and have the same issue with some of the switches (O-72).  I am considering making a dedicated loop with Lionel O track to run the PW stuff.

I need to do a comparision of a 022 versus the Supersnap 072 switch to see what the design difference is.  It is annoying, and I would rather not modify the PW trucks or knock off the shoe.  G

Thanks a lot guys, I'll try all of your suggestions - glad to hear that I'm not alone with this. As a matter of fact, last year I ran some 2343s around and a slider was ripped off by a switch. I miss running some of these older engines but haven't after losing the shoe. Perhaps wiring them up is the answer for a mechanical solution. 

I'm editing the tender number too. Thanks - something didn't look quite right...