99 f150 extended cab 5.4 4wd 4r70w..i changed the fluid and filter(drained the converter).when I take off easy theres a hesitation(dont think its a slip)when it changes to 2nd and when it does sometimes it bangs into 2nd.now when i take off atleast half throttle or more it shifts fine,no lag or bang..no other gear does this.downshift from 2nd to 1st is fine.truck has 250k miles on it..could it be a solenoid or something simple.it dont feel like a slip.does it even when shift it manual.
any help on what to look for?

 

Good bet a control spring is broken that softens the application of fluid to the second gear servo action.
In the valve body is control valves that have coil springs with calibrated operate tension on the valves.
If the spring is broken it allows the valve to slam the servo with a lot of fluid pressure and makes it a sudden or faster lockup of the clutch pack and what you might be feeling.
Good luck.

 

anyone have a diagram of the valve body and the the spring that maybe broken?

 

Unless your comfortable with the job let a shop do the inspection.
The pan comes down, fluid drained, valve body taken down.
There are check ***** to keep track of for location and size.
Valves are in bores that have to be removed to see the springs and not mixed up at re assembly.
A separator plate is part of the assembly.
Re install requires the use of an inch pound torque wrench to be proper.
New filter, gasket and fluid.
Research the job before you begin so you have some idea what is going on.
Good luck.

 

I'm familure with valve bodies,I rebuilt a 4l60e and 700r4 and put shift kits in both and all new valves upon rebuilding them...I did some checking but I'm unable to find a website as to where the check ***** go.