You can use universal sockets with torque wrenches if you know the offset angle. You must set your torque wrench to a greater torque if the plane of rotation of the torque wrench head (the wrench remaining perpendicular to the extension bar) is not parallel to the bolt head plane of rotation. If you have any offset angle the torque applied to the fastener will be less than the torque wrench setting so you must adjust for this.
I think the equation is;
TA = T/cos^
where TA is the applied torque (or torque wrench setting)
T is the torque applied to the fastener
^ is the offset angle.
So if your wrench is parallel to the fastener ^ would be zero and if the fastener spec is 48Nm torque then TA = 48Nm/cos(0) or 100 Nm which is the same as your torque wrench if you are using a regular socket.
If however, you use a 'wobble' extension and the offset angle is 16deg (max possible offset with a 'wobble' extension) then
TA = 48 Nm/cos(16)
=49.93Nm (giving an applied torque of 46.14Nm with an indicated 48Nm at 16deg offset)
at 10deg
TA = 48 Nm/cos(10)
=48.74Nm (giving an applied torque of 47.27Nm with an indicated 48Nm at 10deg offset)
.................an error of -3.8% in applied torque at 16deg offset which is probably less than the calibration error for many torque wrenches..............or the error introduced if you failed to grease the bolts and nuts before assembly.
We will see when my motor throws a rod next summer
