The T-bar is a part of the rear suspension on some cars (like the l4, yoke, corally, t fource).
Here is a picture of the L4 which has a T-bar, it's the white plate under the rear shock.
A link car has a different rear suspension.
Here is a picutre of the carpet knife, which has a link style rear suspension.
With A T-bar suspension the T-bar acts like a sort of spring, but a link car has 2 springs, each on one side to to that.
I guess the pictures say enough...
