This is my daily driver 1974 euro spec 350SE.
If I travel at speed (>100km/h), the transmission pushes fluid out of its breather until its about 0.5 litres below the minimum mark. As expected, due to being low on fluid, shift quality is then poor. If I refill the trans up to the max mark, shifting is great, and all is good until the next time I travel at speed.
This started about 6 months ago, after I removed, stripped and reassembled the valve body due to it having broken a spring. The...