1825 to 1832 John Lankshear in Australia 

General Card Index (yes banks of card deck boxes) at  Society of Australian Genealogists

John Lankshear (a brewer) and another (perhaps a wife) - index shows 2 sailed to Van Diemen's Land (Tasmania) 

Assisted emigrants with a grant of 20 pound this is dated 1825 but has 32 alongside which could mean upto 1832 or under the Emigration Scheme 1832.

From http://portal.archives.tas.gov.au/menu.aspx?search=10

census of 1837 Lankshear John 1837 New Town POL361/1/1 page 98

nothing else so perhaps he moved to mainland 

John is shown as a brewer and following travel could be him

And 1844-1845 Australia Transport - Arrivals - Lankshire has a Mr Lankshire who in 1844 and 45 travels between Port Philip and Sydney

there is also 1870 John Lankshear at Wagga Wagga rather than the son b 1842 to Joseph LANKSHEAR marriage to Sarah Fowler - except he would be I am guessing towards 70 I suppose and it sounds more likely to be the younger John.

See also 1830 John Lankshear marriage Margaret Smith at Westminster, Middlesex - speculation as to if he actually went near to 1832 so could be the John of 1830 marriage.