That gurgling sound you hear is blockage/clogging that is inhibiting proper flow.
The ammonia/hydrogen mixture gets heated (electric/gas) and turns into a vapor then flows by gravity back down thru cooling tubes/fins absorbing the heat (cooling freezer/fridge) and turns back into liquid.
When operated off level that gravity flow is interrupted, over heating occurs, crystals form/stick to tube and cause blockage which causes more overheating and more crystals to form .....etc. The damage is accumulative.
Eventually a tube will get overheated enough due to lack of flow and will crack.
There is no cure......only band-aid fixes.
Replacement cooling units are available.
Check this place out....good rep, good pricing, great customer service and they have new and remanufactured cooling units...
LINK