Couplers

[mongo5573]

How do you change couplers on HO cars?

[richg]

How do you change couplers on HO cars?
[/quote

Very carefully. lol
Which brand of cars?
The old Horn Hook or the newer cars.
Your question is not very specific.

Rich

[Doneldon]

How do you change couplers on HO cars?

mongo-

Such an easy question to ask but so difficult to answer!

Seriously, there are as many ways to change couplers as there are cars which need them. First, there are several different couplers to choose from. Then there is the question of couplers mounted to the car body or on the trucks (Talgo trucks). And, last, there are draft gears (the boxes which contains the couplers) which have one screw, some with two screws, some with snap on covers, others with metal clips that hold the cover on, and some which just screw the coupler to the bottom of the car with no draft gear at all. But take heart. None of them is hard to work on.

The way to remove the draft gear cover will be obvious as soon as you look at it. Some of the clips can be tricky but you can usually pop them off with the help of a small (as in model size) screwdriver. Then you install the coupler of your choice. I'll add some helpful (I hope) hints about that.

If you have Talgo trucks, either replace them and mount the couplers to the bottom of your piece of equipment, or cut the coupler arm off and mount the couplers to the floor of your equipment. It's better to replace the whole truck, as Talgo trucks generally aren't of particularly good quality and they won't allow you to successfully back up your trains. Regardless, at least make sure you have metal wheels if you keep the abbreviated truck.

Knuckle couplers both look more like real couplers than X2f, horn-hook or NMRA couplers and operate much more reliably. Of knuckle couplers, the best looking are "dummy" couplers, which means there are no moving parts. These were used quite a lot years ago but they aren't so popular now because there are very reliable operating couplers on the market. All operating knuckle couplers work together fairly well but the best performance is when all couplers are the same brand. That being said, Kadees have been around the longest (by far) and operate the best. I strongly encourage you to consider them.

Use either the full-size Kadees or the so-called "scale" couplers, but not both. You can buy sort of universal Kadees with or without draft gears, depending on whether you need them. It's cheapest to buy the "universals" in bulk packs (with or without draft gear) if you're going to install a lot of them. There are also specialized Kadees for particular cars or manufacturers, and kadees with different lengths of shank (the horizontal bar which holds the knuckle) and different sets of the knuckle (high, low or middle) to help you equip your cars with a best fit coupler.

The most important thing about good couplers is that they be at the exact same height. The only way to ensure they are is to use a coupler height gauge. Kadee, the NMRA and MicroMark all sell them. If your couplers are too low, raise the height of the whole car by adding washers between the top of your trucks and the bolster to which the couplers mount. Don't use metal shims on cars with metal bottoms because that will give you a short. If cars are too high, lower them by adding shims between the bottom of the car and the draft gear. You can use offset up or doen coupler shanks for bigger changes in height.  Don't forget that up turns to down, down turns to up and left and right change posititions when you have the car upside down for the work.

Next, make certain that your couplers do not sag. While checking that, make sure that the couplers center themselves when pushed to either side.

The thick wires that hang out of the bottoms of Kadees are important for magnetic operation. They should just barely clear the tops of the rails when going through a turnout or crossing. There are special pliers for bending them but you can use regular pliers if you are careful.

Also, make sure that there aren't any little rough spots or casting flash which might interfere with the operation of the knuckle. Last, use a little it of graphite or Teflon to lubricate your couplers, both the knuckles and the draft gear. Do not use oil or grease of any kind. Kadee "Grease 'em" is okay because it isn't actually grease.

Recognize that couplers become misaligned or out of adjustment from time to time so you'll need to build periodic inspections and maintenance into your modeling life.
                                                                                 -- D