after my truck warms up a little my tranny seems to shift very hard from 1st to 2nd and only between these two. If I go from 2nd to 1st and then speed up again the problem doesn;t happen only when I'm at a stop. If I'm in stop and go traffic then after about 20 shifts or so it starts to happen. Right when i start it up everything is fine.

Would this be fixable with a PCM flash or is it something in the transmission itself. And also would I need to get a brand new tranny becuase of this problem.


thanks

 

I don't know what year truck or transmission you have. The 4r70w transmissions are prone to this problem when the lower accumlator spring breaks in the 1-2 accumulator. You may be able to change it with a tune,but still you have broken spring floating around in the piston destroying the bore.
Alan

 

I have a 2000 f150 with a V6 engine and I had the tranny rebuilt about 1 year ago

 

Thats my story and I am sticking to it...
Alan