Converting MTH switchers to 2-rail

 If they have the plastic bottom on the trucks, It's much easier. You can switch out the wheels and throw a 2R/3R switch. Fixing the pilot, adding KD couplers, and perhaps extending the railings down if you want to do it completely.

  If they are older, the axles are pressed into the trucks and need to be pressed out by someone with proper tooling. I've seen an article by John S in this magazine that covers another way to tap out the axles and machine the trucks yourself.

 The absolute easiest, would be to purchase scale wheeled versions in the future.

Most of the Premier line of MTH diesels are set up with the 3/2 switch. You can replace the Hi-Rail wheelsets with scale wheelsets, but you'd still need to fix the pilots and ditch the electronic couplers in favor of Kadees. Some work, but not impossible. The Rail King line doesn't have the Proto 3/2 option (yet) so you'd have to remove the truck blocks and send them out for conversion. Joe at Baldwin Forge does this work and I also heard Northwest Shortline also does it.

As for the rest of it, you'll be surprised how handy you'll become. Just look at setting your layout up with a minimum of 36" radius (O-72) and use #4 turnouts instead of O-72 curve-replacement turnouts and you should be off to a good start.

Hi Pat,

If your switcher(s) don't have the Proto3-2 trucks you also have the option of swapping them for Proto3-2 trucks.  We've been doing that on several engines for one of my 2-rail clients.  The best way to go about ordering the parts you need is to find a Premier diesel with Proto3-2 trucks that match the axle count, pivot location, and wheelbase with the engine you are converting.  With the right parts the conversion can be made with just a couple phillips screw drivers.

This isn't a diesel, but would give you an idea of the flip a switch "3 rail to 2 rail" conversion mechanics.
Russian Decapod.

Note the insulated bearing inserts on the tender trucks.

Insulated bushing insert where the axle and wheel are connected also on the tender trucks.

Third rail pick-up that would be removed for two rail operation.

Right side and Left side are insulated/isolated for two rail operation.

3-rail/2-rail switch and DCS Polarity switch.

Note the non-insulated/non-isolate axle bushing one side only.

There are very good instruction in the operator's manual with the locomotive on how to do the conversion. IMO, the savings to MTH, as the manufacture, is one production line does both 2-rail and 3-rail products.

To hi-jack this thread, which small MTH switchers DO have the 2/3 capability?

Many Thanks.

Rick

Use the search feature on the MTH website. 

 I don't believe any Railking models offer it. It would have to be premier.

 Some larger diesels seemed to start offering it soon after about 2004. However not many, hit or miss. I don't have any premier switchers. I do have a GP that is two rail from the factory. I think there was a push to offer the capability in the late 2000's.

 I always thought that MTH only offered a trade in policy on trucks. Even that was not economical. It seemed better to swap out if you had a donor or sell it out right. I still have a set of G scale trucks that need replacing @$80 each. They were bashed by a previous modeler. All I need is the plastic casing. I save them for spare parts.

"Use the search feature on the MTH website."

That would defeat the point of learning from other's first hand experience.

AND....it would be too easy!

Rick

Baldwin Forge & Machine is 15 minutes North of Timonium, MD. Joe's e-mail is rrjjf@aol.com. He does 3 to 2 rail conversions and is easy going and great to work with.

if the MTH diesel of your choice is not 3/2 compatible, here's what's involved.

purchase conversion set from NWSL

using a puller, remove the OEM wheels

then remove the axles and worm gear

replace wheels with NWSL insulated sets by pressing on.

add wipers for elec. pickup from the insulated side, the more the better.

the most difficult parts of the job are pulling the wheels off without damage to the axles AND pressing the new wheels on squarely. if you don't think your up to the task, then Joe at Baldwin Forge is your man for the job.

Hi Rick,

If you're strict about the term small, probably the only switchers with Proto3-2 trucks are the Also S-2's.

If you open it up to road switchers and smaller road engines that were commonly used as switchers later in their service life there are several, including RS-11's, RS-27's, GP7's, and GP9's.

Thanks Dave.

I will use the MTH search feature and look at their S-2's!

Rick.

I didn't know that was an available option as it would make things a lot easier. 3-2 electrical is a no-brainer as they did that 60 years ago(I have the illustration if anyone wants it).

I was told the same thing but that was years ago. Has something changed? Is it now possible to buy the MTH 3-2 trucks?

Hi guys,

Authorized service centers can order the trucks. MTH does require a truck swap on diesel truck orders, but they have been very understanding about the conversions I've been doing for my 2-rail clients.  When folks want a large number of a certain part all at once they're hesitant to sell them because they don't want to run out of stock for their repair parts.  However, they have been willing on more than one occasion to add on to an up coming parts order from the factory.  We've done several conversions already and I'll be doing a few more soon.  If you value your time at more than $1/hr it's a VERY economical way to convert a diesel from 3-rail to 2-rail.

Thanks a lot Dave. That's awesome!