Having trouble with my 97 f350 powerstroke automatic transmission? The truck down shifts out of overdrive then picks it back up, it was rebuilt about 10,000 miles ago. I replaced the third break light recently because it was a rats nest, figured it would solve the problem but to no avail.

Long story short it's not throwing
any codes, no idiot lights or anything, trans fluid level is spot on, let the truck warm up for 30 minutes figuring it was slipping due to the cold. Please help lol
Someone said it could be turbo lag but this seems more like a transmission issue.

 

Have you ever replaced the manual lever position sensor?

 

no I haven't, I'm not sure if it was replaced by the original owner

 

The truck has 106k miles on it

 

That 3rd brake light only matters because something is drawing its ground connection through it. You may want to check all the ground wires. I had a 97 some time back, and it was acting goofy. It didn't have that 3rd brake light, since it was an F-Superduty. I was advised to check all ground wires running from the body to the frame as well as the batteries. I also ran 2 more ground wires off both batteries, one each to the body, and one each to the motor. And it cured the electrical gremlins.

 

MLp were terrible about water intrusion wich would cause trans to drop out. Make sure all brake lights are working properly tho as john said^^

 

I'm going to add more grounding wires if that doesn't work I'll swap out the mlps

 

Only buy motor craft sensor if you get that far!

 

Does anyone have a part number for the motor craft mlps

 

what speed are you at when it drops out of OD? between 40 and 45 is the magic number. 40 is od off, 45 is od on. if you are rite between 40 and 45 it will drop in and out of OD.

 

Good point Tom. Didn't think of that!

 

the only reason i know about that is because mine drives me nuts on the way to work. the road is a 45 limit, but i always get idiots in front of me that drive 42-43 mph and i have to turn OD off to keep the trans from jumping in and out of OD

 

45-50 mph I'm almost positive that it's the mlps after driving it last night

 

Ok now it's slipping out in every gear

 

Check to see if the trans filter didn't fall out or if the seal is compromise