Removing Proto coupler from engine

I'm presuming that you are dealing with a diesel (or electric) loco ("engine compartment")

rather than a steamer's tender. (Usually steamer tender trucks are mounted by screws accessed from inside the tender shell and usually under some electronics - but not hard

to get to.)

There is typically a large, single screw in the center of the diesel truck "block", seen from underneath. Unscrew this and drop the truck (you may have to turn the wheels to wind

the worm gear off the spur gear - same going back on, reversed). The coupler mount may now be accessed. Some more recent diesels have a truck-mount method that just requires

that you turn the truck 90 degrees to disengage some tabs. I don't have any of these.

Is the coupler mount bent/broken? Is the spring missing? This would cause drooping

and no centering action. 

Anyway, just get to know it. 

It's useful to specify the exact model when you ask questions like this, makes it easier to answer them accurately.

For a diesel, you will have to take the shell off, as when you remove the single screw, the motor will disappear into the shell.

There is a T-pin that centers the coupler in conjunction with the spring.  Sometimes the T-pin gets dislodged and stops doing it's job.

The model is 30-20190-1 it is a gp-7.

That one will have the arrangement I mentioned above.

You'll have to remove the shell, then take out the single screw on the bottom of the truck that holds the motor mount.  The motor will slide out of the truck and you can get to the topside of the truck.  It should be obvious what the issue is when you get that far.

If you have questions, post some pictures of the coupler and truck if you get stuck.

Thanks John I will keep you posted.

You will also have to remove the pilot to access the T bar and get it out to inspect coupler.  Single screw normally.  Watch how wires are routed.  G

I would like to give a big thanks to you guys for giving me advise on how to fix my proto coupler, took the time today to sit down and dive in. John you were right once I got the coupler out it was glaringly obvious what was wrong. When the truck was painted a bunch of paint gathered in the back of the seat were the coupler rides and then was baked on. Nothing a small jewelers file could not take care of. I am going to try an attach a before an after photo so you can see the difference, not the best picture quality. Thanks again.  

It's nice when it's an easy fix, and you have one more skill in your tookbox.