Granted, you can only take what is on Wikipedia with a grain of salt, but has anyone ever seen this claim before? This was the first time I heard that some "lost episodes" had poor audio and Gleason approved of having the voices dubbed? (I know of one episode from VHS - maybe "Bus Accident" or something - where the audio is so poor by the end of the sketch you can't hear the actors, but this is something I had not heard before.)

In January 1985, Gleason announced the release of an additional group of lost episodes from his private vault. As with the previously released sketches, these "lost episodes" were actually kinescopes of sketches from the 1952–55, 1956-57 run of The Jackie Gleason Show.[19] Because the prints had not been stored under ideal conditions, parts of the soundtracks of three episodes were unusable, and voices had to be redubbed. Gleason personally approved the soundalike actors, with impressionist Joe Alaskey doing Kramden's lines.

The episode that you are talking about is "Lawsuit" and not "Bus Accident." Currently, only the syndicated version of "Lawsuit" has the overdubbing and not the one that is available to the home videotape market so to speak. Maybe the Lost Episode DVD Box set that is coming out will have this version.
Why the original DVD release didn't have this version is mind-boggling since the overdubbing happened years before.

On a side note, for the longest time, I always assumed it was Jackie and Audrey that did the overdubbing since they were alive and, Gleason at least, was healthy enough at the time to do them.

Because the prints had not been stored under ideal conditions, parts of the soundtracks of three episodes were unusable, and voices had to be redubbed. Gleason personally approved the soundalike actors, with impressionist Joe Alaskey doing Kramden's lines.
"Lawsuit" was definitely one of them, but I'm curious to know what the other two were. "One Big Happy Family" had some visible damage, but I don't remember noticing any major issues with the audio.

The episode that you are talking about is "Lawsuit" and not "Bus Accident." Currently, only the syndicated version of "Lawsuit" has the overdubbing and not the one that is available to the home videotape market so to speak. Maybe the Lost Episode DVD Box set that is coming out will have this version. Why the original DVD release didn't have this version is mind-boggling since the overdubbing happened years before.
It probably didn't end up on previous releases because it was Viacom, not MPI, that was responsible for the edits. That being said, I doubt they'll include the dubbed over version on the new set. It'll be interesting to see what they do with that one though, since the shows have been remastered.

On a side note, for the longest time, I always assumed it was Jackie and Audrey that did the overdubbing since they were alive and, Gleason at least, was healthy enough at the time to do them.
I think smoking had taken it's toll on Gleason's voice by that time. I've seen the syndicated version of "Lawsuit," and while you can definitely tell where they dubbed in some lines, the average viewer probably wouldn't even notice. Joe Alaskey sounded more like Gleason in the 50s than Gleason himself at that point.

You're right. Gleason was a smoker and his voice was impacted. I just assumed that since he was working on "Nothing In Common" at the time of his death, that I assumed that he was healthy to do the overdubbing.

Now that I remember some of his parts in that movie several years ago, I can remember his voice being impacted.