Modifying a kadee to fit in a Lionel front coupler pocket

Certainly looks like you answered your own question. That is the same process I have used on some models, however the main issue is the height of the coupler. What with the new Kadee 700 series with off-set coupler head heights, they just might be the ticket.

Hot Water

Were you able to use the stock screw?  It looks like the shank behind the coupler might be a bit too small for the stock screw size.  This is a 700 series coupler I am looking at.  I would also consider using a 800 series if the shank is a bit thicker behind the coupler.  

At the time I was doing Kadee up-grades, I only had #805 Kadees availably. I don't have that Many Lionel locomotives, but I generally prefer to stay with the scale "dummy" front coupler, except on 0-8-0 switchers, because they look better and will still couple to a Kadee #805.

 I have a K-Line tank engine that's used in push, pull service. Luckily the coupler pocket was the correct height. The Kadee's posed a problem as there is very little solid metal between the coupler and the hole for the centering spring. Drilling close to the coupler will leave you very little swing If any. I ended up using the dreaded Atlas coupler which has a much longer metal shank. Drilled it out to except the stock screw. A little filing and it works well. It's only pulling 3 GGD Coaches.

 Kadee with it's new offset couplers and long shanked passenger coupler may work. As Hot Water mentioned getting it the right height is key. Most of my steamers seem to need the dropped version Just to be close. Only available in a standard length. I've heard some good things about JB Weld on the Forum. I'm thinking it may be possible to fill in the hole for the centering spring with this and drilling it to accept the stock screw. A little filing and it may work. Just not sure how durable this stuff is. Probably fine pulling rolling stock. Not sure how it will hold up as a trailing engine. 

 I doubleheaded 2 Lionel Mohawks at one time. I used the Atlas coupler on the trailing engine and seeing I ran them as a tandem. I set the Head engines tender coupler at a matching height. Worked very well.

I can try to use one of the Atlas couplers, as I have plenty of them.  The shank behind the coupler does have some more "meat" on it.  

If they are the "older Atlas couplers", I would sure be careful of those. Virtually every one of my Atlas cars that came with those "Adjust-A-Coupler" set-ups, had knuckle failures. I finally removed them all and trashed the whole bunch!

they are but I have tons of them so I can make up a bunch to fit in the coupler pocket and if one breaks I can just switch it out.  Heck they are free so why not.  

So I tried this today on my legacy 10 wheeler and it works great!  I ended up using an Atlas O scale coupler since the shank behind the coupler was a bit thicker. 

On the ten wheeler the coupler ended up being the exact height.  I think I will try with a 700 series kadee though, since I can get under and over set couplers and I like the look and operations of them better.

I did try to double head this with one of my other kadee equipped locomotives and even on my tight O48 curves it worked great.  

Well just tried it with a kadee and it is a no go, the shaft is just not thick enough.

I might have a few 800 series couplers around and I will check them when I get a chance.