Some children go on a travel adventure – at one point they are being chased by a lion while driving in a sort of Land Rover and someone throws a shoe at the lion and hits him on the nose – illustration shows lion knocked on his butt with a swollen nose.
Is this definitely a picture book, or could it be an illustrated chapter book? If the latter is a possibility, then it might be one of Willard Price’s ‘African Adventure’ series, illustrated by Pat Marriott. I know that one of the books is definitely about a lion.
Another possibility, perhaps more likely as it is a picture book, is a Ladybird book from 1961: David Scott Daniell and Jack Matthew: ‘Flight Five: Africa – A Ladybird Book of Travel Adventure’