Flames tore through the lorry leaving it an empty shell on the carriageway on Monday morning.
Firefighters and highways officers were called to the M6 between Great Barr and Spaghetti Junction shortly before 7am on Monday.
The M6 was closed between Junctions 7 and 6 southbound, as crews brought the blaze under control.
A West Midlands Fire Service spokesman said: "We received a 999 call at 6.52am reporting a large vehicle on fire on the M6. We sent three crews to the scene, a total of 15 firefighters.
"The fire involved a curtain-sided lorry which was fully destroyed by the fire.
"The cause of the fire is not believed to be suspicious."
Queues snaked back more than four miles towards Junction 9 at Wednesbury. Crews were able to reopen the M6 northbound and lane three southbound later in the morning.
The lorry was cleared from the route by around 10.20am but lanes one and two southbound remained closed until 10.40am.