This thread shows how to convert 3-rail couplers to Kadees on Atlas cars.  The first section will show you what you need to restore the 3 rail couplers.  This is the assembly you need.

You may want to post a WTB ad for a Atlas 3-rail coupler assemblies removed for 2 rail conversions.  Someone might even gift it to you.  Alternatively, you will need to buy a replacement set of Atlas 3-rail trucks with couplers. Here is a link to a set from Mr. Muffins Trains.

Bob

@tsheridan posted:

I just purchased a

Atlas 8224-2 O Gauge Hooker 11K Gallon Tank Car

sorry for the large font - I did not realize that it had a Kadee coupler which is not playing well with the Lionel/ MTH train cars that I have on my layout

is there anyway to easily convert the Kadee couplers to the “regular” couplers on the other cars ?

thank you for any recommendations/ advice

tom

If the car has Kadee couplers, it is most likely a 2-Rail Scale car, i.e. 2-Rail Scale trucks. The only way to convert it to a 3-Rail car is to remove the Kadee couplers and change the trucks to 3-Rail trucks with the included "Lionel" style couplers.

Good point.  That is true, unless he bought this one sold recently by Trainz which someone converted to Kadees but left on the 3 rail wheel sets.  Either way, he may end up buying new trucks.

Bob

I bought some 2 rail Atlas cars with Kadee couplers.  Bought Atlas trucks to convert then to 3 rail.  The Atlas couplers cost 60% of what I paid for the car.

Thank you for the detailed instructions

and yes - I just received from Trainz ! - how did you know ?

I’m back in this hobby after a loooiooing hiatus and would normally get annoyed/ ask for a return - but with assistance from people like you guys on these forums I find them learning activities

thank you again

I might have what you need. I do the opposite and convert to Kadee’s.  A picture of what you have would help. If the mount for the coupler has been lopped off for clearance. You need the mounting piece. I’ve come across 3 different ones. There’s a line up molded in boss that seemed to change locations in different production runs if you need that piece. The couplers changed over time as well.

They at one time offered what was a truck mounted 2 rail coupler. In the box you got this piece minus the 3 rail mount. So these parts are out there. I have a box of removed parts and may have what you need. In fact I still have a few cars in boxes waiting to be converted. I don’t know what you paid for the car. If you have no local source to buy new trucks. Your looking at close to $40 for new trucks.  I’ve seen Atlas cars at shows for less than the price of new trucks. At one point. Atlas changed the truck design. They made the sideframes thinner. Bringing them more into scale. Not a big thing. But on a tank car and the trucks being more visible. They do look better. If you go for new trucks go for the latest version.