I regularly get questions from people confused and/or overthinking coupler mounting. I think it is more so overthinking about coupler mounting, not reading the information we provide, and not using the coupler conversion information we provide online. This is something that is a much bigger problem than one might think. This is not just from new people entering the hobby; this is from the hobby veterans also. I will break this down into different common scenarios.

HO Scenario #1: I have an old Example (UP 1234 car) or (B&O loco that has yellow lettering) I picked up; what at coupler do I use on it?
Sorry, we need the make and model of the car to look it up in our coupler conversion list; we can’t identify cars if you don’t know the make and model of a car. You must research it online, ask a railroad forum, or visit a railroad club or local hobby store. Then look it up in the coupler conversion list. https://www.kadee.com/convpl

HO Scenario #2: I am trying to use your product photos to determine what coupler to use for a car, comparing the factory horn hook coupler that came with the car or asking if we have a cross-reference listing for the Kadee® coupler to a horn hook part number.
Use the coupler conversion list. https://www.kadee.com/convpl Remember Kadee® couplers use the NMRA standard mounting height that is measured from the centerline of the coupler head. The coupler you are replacing may not be mounted at NMRA standard mounting height and will need to be adjusted if not at NMRA standard mounting height.

HO Scenario #3: People look at the underframe of an old car and try to guess what coupler height to use.
Use the coupler conversion list. https://www.kadee.com/convpl Remember Kadee® couplers use the NMRA standard mounting height measured from the centerline of the coupler head, not necessarily where or how the old coupler was mounted.

HO Scenario #4: Asking what Kadee® coupler to use to replace the clone knuckle coupler that came with the car they just purchased or a car that hasn’t even been released yet. If it hasn’t been released how are we supposed to know!
95% of the time, clone knuckle couplers factory installed use the Kadee® #148 as the direct replacement. It is really simple to double-check and verify; look at the clone coupler; if it is a centerset, it would be a #148. The long shank option would be the #146 if you have tight radius corners.

HO Scenario #5: Mount couplers using an incorrectly mounted couplers on another car, as a height gauge. “My cars barely hook together and keep slipping apart, and some of my cars, the trip pin hits” “I don’t know why.” “Did you use a height gauge to check coupler height?” “No, I don’t own one, I had a coupler on another car...” You Must use a coupler height gauge to set your coupler height correctly.
Stop and fix the problem. Instead of compounding the problem, mount the couplers properly. Use the #205 or #206 Kadee® coupler height gauge height. Trip pins are factory set. If the couplers are mounted at the correct height, Trip pins will clear properly installed magnets. If couplers are mounted at the correct height, trip pins should not need to be bent. If you are bending the trip pins you couplers are mounted incorrectly.

Large-scale coupler scenario: I have brand multiple brands (brand “A,” “B,” & “C”) of large-scale cars they won’t run together. Kadee® couplers fix this issue easily. Making different brands of cars play nice together is another of the Kadee® coupler’s features. By simply looking the cars up on the large-scale coupler conversion list https://www.kadee.com/lscc and mounting the couplers.
Running multiple brands together can be done with a transition car with a Kadee® coupler mounted correctly on one end of the car and the original coupler mounted on the other for each brand. Then you can run all the same brands of cars grouped; you can connect the different brands using the cars with Kadee® couplers. The other option is swapping all the car’s couplers out to Kadee® couplers, and then you can run the cars in any order you want.

The rest of the large-scale scenario: I have brand “A” & “B” cars that want to change brand “A” and “B” couplers to Kadee couplers to work with brand “C” factory couplers at brand “C’s” coupler height. SCREEEEEECH! Back up! You want to do what! NO! NO! NO!
Kadee® couplers don’t work that way. Each brand of large-scale cars uses its unique proprietary coupling system at its unique coupler mounting height. Kadee® couplers are a standalone product to make the different large-scale brands of cars operate together, but only at NMRA Kadee® mounting height. NOT other manufacturers’ coupler heights or with other brands of couplers. Kadee® couplers are designed to work with other Kadee® couplers. They may hook up to some other brands at a basic level but will not function the way they are intended to operate.

All Kadee® couplers must be mounted at the correct NMRA coupler head height using a Kadee® coupler height gauge for the particular scale you are modeling to function properly. The offset heads and gearbox styles we offer are to accommodate the different mounting platforms and mounting heights with which different manufacturers equip their equipment with and nothing to do with the style of couplers that come originally equipped with your car or locomotive. Coupler head height and mounting on the centerline of the car is the most important things, so proper mounting has to be done backwards, so to speak. When the coupler head height is set correctly, then you have to determine where and how the gearbox can be mounted to the car so it doesn’t change the coupler height. It may seem backwards but coupler head height is so important for a proper functioning coupler. If the coupler is not mounted on the centerline of the car, the trip pin may not open the knuckle properly over the uncoupling magnet. I can’t emphasize it enough, mounting the coupler correctly is so important.