91 auto overdrive problem

[farrier6]

I have a 91 1st gen 100% stocker. It has an automatic tranny. The overdrive only seems to work when the temp is cool outside. During the summer when its hot out the overdrive will hardly ever kick in. In the cooler months it will alway work until the tranny warms up and then once I slowdown to where it kicks out it wont work again until the tranny cools off. WhAts up with this?

 

[Whit]

have you changed the fluid and filter lately?


I would take it in for a flush and see how it acts then

 

[ford5.9]

Shifting problems

Have you tried changing out the temp sensor on your trans line. IF the fluid gets over 270 degrees or so it will open the circuit to the PCM, causing it to drop out of OD, to keep the trans from burning up. If you have figured the problem out, what was it?