Sync of video from one source to audio from another source (same content)

[tbbttbbt]

Let's say I have two TV recordings from the same show but one is in english and one is german.
The english video file is a better quality so I would like to sync the audio from the german video file to the video from the english version.
But two problems.
Problem 1: It doesn't help to change the audio delay with MKVtoolnix or any other tool, because then it's out of sync after 30 seconds again and the pitch is still wrong.
Problem 2: Changing the speed helps the pitch problem, but the audio is still out of sync after a few seconds.

Am I missing something?
Is there a better software solution that automatically syncs it? (Doubt it, but still asking)
Anybody got any ideas?

[hech54]

If there are no drastic differences in the "cut" of the video(identical scenes and everything), I use an old free version of Reaper to change the playback rate of the new audio until it matches the original.
Load both into the program so you can see the waveform.....it takes a lot of time but it is done correctly.
I've heard you can do the same in Audacity but I learned to do it in Reaper. The very first versions of Reaper were free.

You need to right-click on the new file's waveform in Reaper to bring up properties....and the playback rate change option is in there. Obviously a short video is easier to work with than a long TV episode or movie. I work with music videos that are usually under 5 minutes.

[manono]

Problem 2: Changing the speed helps the pitch problem, but the audio is still out of sync after a few seconds.

From what speed and to what speed did you change it? If one source is PAL and the other NTSC, a simple 25->23.976 fps should work, with perhaps a final delay afterwards. This is assuming, as hech54 mentioned, the content is the same (same number of frames).