I found the same thing with my situation
I have modified my Thrustmaster T2 with springs from an auto parts
supply house, rather than a hardware store.
You will need to take the pedal unit with you, but there are
generally a myriad of different kinds of springs and the like at
places like that and they can usually fill the bill easily.
In all, I clamped the actual pedals to the pedal levers eliminating
the need for the terrible little springs on them, and as far as the
throttle and brake return springs, you can find "in-line" springs
manufactured for autos and farm equipment carburator return springs
and modify the floor unit to the T2 to allow you to use them instead
of going thru the mess of trying to get in touch with them and all
that. The automotive springs have a secondary benefit as well, as
they will last longer, without the possibility of breakage with the
frequency as the Thrustmaster T2 springs would.
If you need any assistance with this modification contact me at
and I will do all I can
Doug