Coupler failure

[jonathan]

After three years of running my layout, I finally experienced coupler separation.  It happened while running a double-headed train with 22 freight cars and a caboose.  I was running the trains at about 70%... a bit faster than I normally run (was feeling speedy that day). The Athearn engines (SD70M and GP40-2) separated.  Later, two freight cars separated about halfway through the consist.  So I'm ready to pull the trigger and order a bulk pack of kadee #148's.

Will the #148's be compatible with all my fleet?  I'm capable of minor tweaking (filing, sanding, shimming and drilling).  I'm also considering #5s, but would rather not play with the separate centering spring if I can avoid it.

I have Athearn, Atlas, Bachmann, Metaltrain and Walthers rolling stock and locos.  Think I read somewhere that putting metal couplers in some engines can affect current flow, although I could be wrong about that.  I perform regular maintenance on my track and wheelsets (all metal) to keep everything free-rolling. There are no uncoupler magnets under the mainline.

Regards,

Jonathan

[rustyrails]

The 148 has the same size and shape shank as a #5, so I would think you could use them in most applications where there is already a knuckle coupler in a draft gear box.  Truck-mounted couplers are another issue.  Check out Kadee #21 through #29 for that application. 

Back in the old days, pre DCC, locomotives had the frame connected to one rail.  If Kadee (metal--that's all there was) couplers were mounted in the draft gear box that was part of the frame, and then that loco was run back-to-back with another engine with couplers mounted the same way, a short would occur through the coupler.  The fix was to either modify the frame or the body to accept a Kadee plastic draft gear box.  Problem solved.   Hope this helps.
Rusty

[Guilford Guy]

Kadee #5s should be compatible with any other knuckle coupler aside from Sergent Engineering and Dummy Knuckles. The current issue you speak of is because the majority of locomotives have metal frames. The Kade couplers are all metal, thus if the trip pin catches a frog it may or may not cause a short. If your trip pins are all at the correct height this won't happen.

[jonathan]

OK, thanks.  That makes sense.  I checked out my LHS yesterday and found a 4 pack of #5s for 3.50.  I located the offending freight car and started surgery.  Turns out that car had those knuckle couplers that come in two halves.  Dumped 'em and in went the #5s.  The centering spring wasn't that hard to deal with. I actually use a No. 2 pencil to lube my draft gear boxes.  Did I mention I'm 'frugal'?  It wasn't as hard as I thought it would be.  I also replaced the couplers in my GP40.  So far no problems with shorts.  Looks like I will take my time and replace all my couplers as the old plastic ones give out.  Thanks again, GG & RR, for all the great wisdom.

R,

Jonathan

[jward]

the shorting out through the couplers was a particular problem with older athearn locomotives, the ones with the plastic clips holding the souplers to the frame. if both locomotives were pointed the same way there was no problem, but running them back to back made the frames opposite polarities, and they'd short through the couplers. this problem has been solved on the locomotives with the  plastic draft gear boxes that slip through the pilot.

the solution was rather simple, replace the plastic clip with a draft gear box. you'd have to drill out the hole in the coupler mounting pad and use a 2-56 screw to secure the draft gear box. also, a #5 is too low, you have to use a coupler with an underset shank to get the correct height. i used one of the 30 series couplers, i think it was #32, for this application.

on the athearn cow and calf, aka sw7, you have to use a different solution. they used tha same coupler mounting as the freight cars, with the metal clip holding the coupler in place. i'd use a plastic shank coupler on these.

[ebtbob]

Jonathan,

       I think,  if possible,  the use of the Kadee 148 should be your coupler of choice.   You said that you have some Walther's rolling stock.   Walther's cars,  historically,  have shallow coupler boxes.   I have experienced,  over time,  that the installation of the Kadee 5 and that centering spring,  do not fit well.  As you tighten down on the screw to hold the coupler in place,  the height of the spring and coupler cause the coupler to bind.   By using the 148,  no plate,  no binding.
       Any new couplers that I install get the 158.   I like the semi scale size of that coupler.   But.....I never use the semi scale couplers on my engines as they tend to separate too often.

[jonathan]

ebtbob,

Thanks,  I think I will mix between #5 and 148.  I was unaware of the shallow box in the Walthers (haven't changed one yet), but I did discover that a few of my old Roundhouse kits had shallow gear boxes.  Was just about to order some 148's.  Think they're on sale this month in one of my flyers. Glad to know there a good fit.  BTW this is really for a new thread, but I went through three LHS's today (local is relative), and it's amazing the lack of inventory in all of them.  It's seems to be getting worse and worse. I hate buying on line.

Regards,

Jonathan