Well I took my truck out the other day. I just put a complete lightning motor setup in my 68,000 mile truck. My 4r100 has a ftvb for over 20,000 miles now. I change the tranny fluid every 25,000 miles. The tranny fluid is at proper level and is not burnt. On my way home while accelerating on the highway my truck won't shift into third. The od light is not blinking. My tranny temp was 185 degrees. What could be the problem ? I checked the site and couldn't find anything with all these issues.

Any help is appreciated.

 

It could be many things. The first thing to do is see if any codes have been set.

 

I believe you change the control valve with the swap.
Here us some more stuff.

https://www.f150online.com/forums/ar...wap-notes.html

 

Go over to Lightningrodder.com and PM blower ****. He's one of the top guys to talk to about the 4r100 trans.

 

No codes set.

Thank you for suggestion

 

My truck came originally with a 4r 100.

Thank you for suggestion

 

I pm'd him

Thank you

 

You need to remove all the connectors on the transmission and check for damaged, broken, dirty, or corroded pins on BOTH sides of each connector.There is one on the passenger's side that is the most likely to cause your problem, but there is also one on the driver's side of the transmission that can cause problems.

I've never seen a valve warp. Valves stick, usually from debris or wear in the bore. There are no seals or orings to check. Sticking valves and broken springs are what to check for. http://atransmission.info/4r100-shif...sure-cure.html