I fixed mine.(the turning was getting hard to the left,the speed worked fine)
Took it apart,cleaned it with some rubbing alcohol,cotton swab.
Added a thin piece of plastic,where it makes contacts to the board for turning.
It worked great for awhile(month)...then I decided to clean/scrape the connections in the plug,while at the lake with my pocket knife.Should of disconnected it from the battery,one little spark and lost my speed control,still turned but no speed.
Kinda wrecked my day on the water,don't realize how much you depend on the TM till it's broke.
There's repair manuals to be found online that can help you abit and there's always a new foot pedal to be bought online if it goes bad.
For me,my old PD was 13 years old,the foot pedal fixed by me(how long it would have lasted?)and then I messed up the circuit board....figured to much to fix so made it into a hand tiller model,using a traxxis var. speed motor.