For a few months now my 97' F-250 5.8 4x4, wouldnt shift out of first gear off and on. It just now has gotten to the point where it will not shift out of first consistently at start-up. It will shift out of first at about 45mph but it'll buck all the way up there, and the rpms will go nuts and a have random throttle response. Once it does shift out of first it will shift smooth for the rest of the ride until I restart it. I've changed the fluid and filter, the ATF looked great. I replaced the spark plugs, cap, and rotor. No check engine, and the only code I have is 633. Could 633 be affecting the transmission. Please help this is my first vehicle I bought it myself, fixed it for a full year, and two weeks after I got my license the tranny started acting up. I'm already $4000 in and am working 70 hours a week as a 16 year old. I already brought it to one mechanic who ended up not fixing the problem but got $400 out of me.

 

It could be a bad solenoid, but I think it is more likely to be a sticking 2-3 shift valve in the valve body. That can be accessed by removing the pan.

 

 

I noticed that the transmission always seems to shift well when the truck is warm. Does that confirm your 2-3 shift valve theory?

 

Not trying to be a smartss but if it works when it is warm you could just move south. Good fishing in Louisiana. I guess I am just being smart, sorry.

The relationship to temperature should be ruled out. You have temperature related programming. Hook up some diodes to the signal wires going to the solenoids and make sure you are getting the signal for the 2-3 shift. At least make sure the wiring is good at the plug to the solenoid body.

 

It doesn't confirm it, but it adds to it. Valves tend to stick or be free at different temperatures.

 

Any chance you can give a diagram or location of the wires you suggest I should test.

 

This might help. I couldn't find what I wanted but this might give you some direction.

https://www.ford-trucks.com/forums/1...s-harness.html

This one might be better:

https://www.ford-trucks.com/forums/1...k-failure.html

 

I am now realizing that I wasn't out 3rd, but 2nd gear which changes everything. When I manually select 2nd it runs fine which makes me think it's eletrical, could it be the solenoid pack?

 

I am now realizing that I wasn't out 3rd, but 2nd gear which changes everything. When I manually select 2nd it runs fine which makes me think it's eletrical, could it be the solenoid pack?

 

If it is electrical you will have electrical codes stored.

When in manual 2 the intermediate band is used along with the intermediate clutch. This makes me think you have a problem with the intermediate clutch, or a failed intermediate one way clutch.

 

Here is a video of the failed 1-2 shift

 

The truck was working fine again until now. I have code 633. It will shift at about 45mph but buck all the way up. And then it will shift smoothly for the rest of the trip, even from stop lights.

 

E4OD PCM Swap and Trouble Codes - 1948-Present: Ford F-Series Trucks - 4WD Mechanix Magazine 'Tech and Travel' Forums

This might not apply but it might be good reading anyway. Run searches on anything that gives you ideas. I know it's a lot of information but go back to the beginning of this thread and start over.

I'm still hoping that you might not have internal damage to your transmission. The other problem area with these transmissions is the MLPS. It is called the TRS in later descriptions. Read some about those also.

If you get all of the electrical connections to the transmission cleaned up and fixed up; switches and sensors and solenoids checked out; fluid and filter clean; hoping you'll be good to go for a while.

 

Thanks slot. Is the VSS mounted on the transfer case?