I have a 2004 f150 5.4 new body style truck with a 4r75w trans that is having some shifting issues. It is shifing harder than normal going into second when taking off and sometimes will search back and forth and bang. It doesnt always do it. There are 85,000 on the truck and the fluid has been changed twice. It will not set any codes and is not a steady problem. I tried cheaning the mass airflow and it did nothing. Anyone know of anything?

 

I have the same problem and still hadnt found a solution.

 

This probably is not your problem. But, the 4R70W used to break the upper spring in the 1-2 accumulator causing a hard shift. When I reprogrammed my 4R70W in my 02 truck, it shifted hard and I thought incorrectly that I had set it back to stock and it was shifting really hard. I bought new springs and this is when i found out that the upper spring is 2 springs in mine. Then i tried the reprogramming again and fixed mine.

My 95 Mark VIII Lincoln 4R70W had a slooow soft shift and I changed the upper and lower springs in the 1-2 accumulator and changed it to a quicker crisper shift.

 

How do you change out the upper Springs? Does it require any kind of special tools?

 

Did you ever figure out how to do this job?