1998 f150

4r70w rebuilt 3ed time only 15-30k on the rebuild

4.6 / 5.4 swap...

drove truck on stock 4.6 tune and my tune for my 5.4

My truck has been doing this sence the rebuild.


ok so when i slow down or start from a dead stop the truck will jump to 1000 rpms maybe a lil higher like it should then drops down to around 700 rpms lugging the motor then jumps or slips about 200 rpms then do it again and again untell the truck is running normal. Some times the truck works fine and will speed up like it should.


Now i have looked this up befor and i have a feeling it has to do with the valve body because 2ed gear is always been my problem with rebuilds.
but from reading around this seems more like a shudder problem from fluid and other things.

could this be a vavle body problem ?
what parts should i replace .. springs and such??
i dont think any thing in my vavle body has been replaced..