The work will see the installation of a super-span gantry which will extend across all six lanes of the motorway and the hard shoulders just south of junction 34.
The motorway is scheduled to close between 8pm and 6am on Friday 19 and Saturday August 20.
During the closures, drivers on the southbound M6 will leave the motorway at junction 34 and be diverted on the A683 via Lancaster onto the A6 and then south through Galgate to re-join the M6 at Junction 33 and continue south.
Northbound traffic on the M6 will leave at junction 33 for Galgate and will follow the same route in reverse - via Lancaster and the A683 to re-join at junction 34.
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The M6 Junction 34 northbound off-slip will also be closed Wednesday 17 and Thursday August 18 between 8pm and 6am, and the southbound on slip on Thursday August 18 between 8pm and 6am as part of the gantry work.
The Lancashire County Council road project undertaked by contractors Costain started in January 2014 and is due to be completed late autumn 2016.
The improvements around junction 34 include the improved motorway slip roads and a 600-space park and ride site just off the junction.
For up to date schedules of roadworks visit www.lancashire.gov/Heyshamlink
The Highways Agency provides live traffic information via its website http://www.highways.gov.uk/traffic-information,