4R44E rough shift when cold

[fordalltheway]

I have a 1999 ranger 6 cyl with an automatic 4R44E transmission, 2WD. My problem is that is often has a rough shift from 1-2 when it's cold. Shifts normally when warm. It also seems like it shifts a little late at a slightly higher RPM than it should, not much though. Reminds me a little of a vaccum modulator problem.

Any advice?

 

[richbeme]

similar problem here

i just changed a 4r44e trans from a 2003 with 55k miles on it and when its snowing or wet it was shifting fine in 1 and 2 but when it hit 3rd it would disenguage till it got warmed up it seems, i changed the speed sensor and it seemed to help a little but the problem came back to where until it warms up it doesnt shift right. i have a 1998 with a 6 in it.

 

[fordalltheway]

when you say disengage does the engine rev up? If so I'd call this slipping. I'm not an expert on these computerized transmissions but I would image they still use hydraulics to actuate the bands. In an older trans if the band did not engage you might get these same symptoms and could easliy very with temp as metal expands and contracts. Low fluid level would also cause this to happen as it will effect internal pressure levels.
I think the computer in the "E" version trans basically tells it when to shift.

Mine only shifts rough usually just once when cold then works great. Maybe 20% of the time it shift normally when cold. No check engine light no other symptoms other than I get 18mpg which I think seems a little low. I would think a throttle posistion sensor would have some other symptoms related to engine preformace.