2007 f250 4x4 shift on fly will not work. switch to 4x4 high light will not illuminate and it will not go into 4x4. i have tried in park, in neutral, rolling are stopped. both lights work when you turn ignition key to on. any ideas

 

Do you have automatic hubs?

 

yes i have automatic and manual locking hubs

 

Sounds like you have an ESOF vacuum problem then. Or a possible bad hub. Check for vaccuum leaks

 

Does your a/c start blowing out the defrost when you switch to 4x4?

 

no still blows thru regular vents

 

since your 4x4 lights do not come on check your fuse! even with the vacuum problem your lights should still come on

 

i dont think its a problem with the hubs, cause you said the 4x4 light wont come on. the light should still illuminate, you may have a problem with a solenoid or something else i dont really know much about the system on the 250s (this is my first one). i think the o rings are bad on mine cause when i shift to 4x4 the light on the dash comes on but the hubs dont engage, i have to do it manually. maybe someone else will chime in later and know more about it.

 

yes, you have blown your seals.. I have the same problem but for the amount it costs to fix I can get my lazy a** out the truck and lock them manually

 

If the light on the dash doesn't come on, the transfer case hasn't completed the shift. The hubs are not involved in this whatsoever.

Check fuses, and swap the shift relays with each other. One relay shifts INTO 4x4, the other shifts OUT of 4x4. If it goes into 4x4 after swapping the relays, swap them back and then shift out. Get a new relay and replace the bad one, or just get two and replace both.

I'm not sure where the shift relays are on a 2007, but on my 2001, they are near the master cylinder, near the power distribution box, but in a separate little two-relay box.

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To the person with hub issues, disconnect the vacuum line right after the vacuum solenoid, before it tees off to both front hubs, and check for vacuum with the engine running, and having someone switch it to 4x4 and back a few times, waiting 10-20 seconds between each switch. If there's vacuum there, you have a hose or seal issue further down. If there is no vacuum there, the solenoid is bad, or the vacuum supply is compromised in some way.

 

thanks for all the input. shift relay was bad.

 

I thought your original post said the light did work, sorry clp5!

 

Krewat, Thank you for your post. This is exactly what was wrong with my truck also. I went to two different shops that wanted to charge me $150 to $350 to "fix" it. $35 at Ford dealership....done!!!