Lionel SD40-2 Rear Coupler Problem

I have a Chessie SD40-2 with a rear coupler that tends to uncouple randomly. The track is flat (GarGraves on ultra-low pile carpet), the
couplers line up just fine when coupled. It doesn't seem to make a difference whether the coupled car is heavy or light.
Is it wise to attempt to disassemble the rear coupler assembly and try and stretch the spring a bit to tighten it up?
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Spender:
I am speaking from memory, because my only Lionel cars are buried quite deeply in a box,but I *think* these newer couplers have some sort of plastic latch, right? Could the latch just be rounded off, and no longer willing to grip? I suggest careful disassembly and inspection before you try fixing it...if you can even take it apart. Hm. I really need to look at a Lionel coupler...
Cordially yours: Gerard P. President, a box of track and now some L-girders.
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On 15 Mar 2007 08:39:32 -0700, snipped-for-privacy@gannon.edu wrote:

It is a plastic coupler. The problem seems to be the range of movement of the entire coupler arm. A very slight push up on the coupler arm uncouples the coupler. So it is working as it should, it is just very, very sensitive.
I think the problem is the GarGraves track laid out on carpeting. It's just the way the track is - not entirely flat; it really needs to be tacked down to a solid surface. The uncoupling seems to happen when the loco runs over a slight dip in the track, or a section of the track tipped slightly to one side or the other.
It never happens on the FasTrack.
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