Triumph Thunderbird LT Owner's Handbook Manual page 132

Specifications
Tightening Torques
Oil Filter
Sump Plug
Spark Plug
Fluids and Lubricants
Engine Oil
Brake Fluid
Coolant
Bearings and Pivots
132
Thunderbird Commander and Thunderbird LT
7 lbs ft (10 Nm)
18 lbs ft (25 Nm)
15 lbs ft 20 Nm)(
Semi or fully synthetic 10W/40 or 10W/50 motorcycle
engine oil which meets specification API SH (or higher) and
JASO MA, such as Castrol Power 1 Racing 4T 10W-40 (fully
synthetic) engine oil, sold as Castrol Power RS Racing 4T
10W-40 (fully synthetic) in some countries
DOT 4 Brake Fluid
Triumph HD4X Hybrid OAT coolant (pre-mixed)
Grease to NLGI 2 specification