EO4d problem #9876

[Shadetreemechanic]

My tranny won't go into overdrive. Its not the button cause pressing it unlocks the torque converter as if it were going to shift. OD light is flashing. It seems to go through 1st and 2nd and right into d at about 25 mph.
I am one year into a full rebuild, at that time I also replaced the speed sensor in the rear axle, and the speedometer. Last week I replaced the tach sensor to try to fix this problem. Last week it was intermittant and didn't give me a blinking od light. Today it stayed on even when I turned it off and restarted.
Any ideas appreciated.
Thanks

 

[Ironman03R]

Check your basics first. Is the fluid clean? How many miles on the fluid?
Check the FIPL (TPS) adjustment. Theres an article on this in the tech section.

 

[Shadetreemechanic]

The fluid looks fine, it has about 20 k on it. It was too late to check the FIPL tonight. I tried to buy one to have on hand, but the parts place didn't have one in stock. For about a month my torque converter has been intermittantly not locking. I was told it was the tach sensor, but didn't actually replace it until Sunday after it started this business.
I want a zf-5 so bad.

 

[h2odrx]

I want a zf-5 so bad.

I've got one for ya!!

I'd even meet you half way, I'm 10 hrs from ya due east.

 

[trackspeeder]

Could be a stuck valve or bad solenoid.

 

[Shadetreemechanic]

I dunno. I checked the FIPL sensor and wiggled all the connections top and bottom, and then disconnected the batteries.
I've now put 200 miles on it towing 7k and have had no problems. I did notice that one of the holding tabs was broken off the FIPL connector so that it wiggled abit. I had been pretty far off road the first day it happened and wonder if I shook the connector loose.
Thanks for the help.