MTH Conversion Question/help needed

 Is this a newer model that is 3/2 version? 

 You decide on the coupler brand you want to use. If KD, there are different models to help. I would strongly suggest that you use the standard center shank model, and shim or cut to get the right mounting height when that's possible. So if you're going to convert your whole fleet, a KD coupler height gauge might be a good investment. You could make your own. Just make sure you standardize your coupler heights on everything. You'll also need small drills and a tap for the mounting screws when there's none there. If your engine is newer, the holes should be there. Sometimes there's a bag in the box that even has the shim already cut for KDs and the screws.

 Most MTH engines, have the electric coupler wires running to a plug that you just disconnect.

On the MTH pass cars, they sell trucks that are 2 rail. The biggest issue is that they don't have many choices to match their own cars! So in your case, you maybe  better converting your trucks? or using a different brand.

https://mthtrains.com/sites/de...ction/20st15717i.pdf

I have always wondered if these 3 rail models had larger flanged wheel sets (not main drivers) that were insulated? The instructions says this one is convertible? I always thought it was just the scale wheeled version that was easily convertible?

 The newer Proto 3 0-8-0’s are set to go for Kadee’s. They even supply the brackets. I run Kadee’s on everything and make my own mounts. I have a 2 rail, 3 rail 0-8-0. They didn’t supply any brackets. 

 These are pretty user friendly to work on. Remove the front coil coupler. I make a mount out of brass strips. Get the Kadee fitted and then measure out the new bracket and mark where the hole is on the chassis for the T bar is to mount the coil coupler. I’m pretty sure it’s a #10 threaded screw that will snuggly fit the hole. Drill and tap the brass mount for it. The pics. Below are of a Lionel conversion. The MTH I do the same way.

   Adjust the height as needed and tighten up the screw.

 For the rear. I make a T shaped bracket from brass strips. I solder the T together. You will need to drill out the chassis to mount it. I usually tap the chassis to receive the screws. This again is a Lionel conversion. I do the same thing for MTH. I added some extra brass to sort of frame the coupler in a little better and added an air hose. Just used JB Weld for this.

You

 This is a PS2 that I just finished up.

 Here’s a video of it. A little better look at the Kadee.

AWESOME! Thanks guys.

I worry that those large flanged wheels are only good for 3 rail track!

I think you may be right Joe.  I looked at one of my more recent MTH locomotives with the 3/2 rail capability, and when I set it on my test piece of 2-rail Atlas track, the flanges hit the ties.

I had asked about that issue from somebody else here on this forum a couple years ago, I think his name was Matt and he was at the club in San Pedro. He said the only problem was the switches, something my layout intentionally doesn't have. I have ran an 0-8-0 PS2 and an AEM-7 PS3 on Atlas scale 2 rail track with no problems at all. Both have hi-rail wheel-sets....