Wow, this has been covered so many times in different threads, "but" !!

I've done it all, Replaced hubs, vacuum canister rsv. lines, pulse solenoid, pump works as should, Tested with vacuum tester.

Here's what happens, 4wheel is instant and great it just doesn't unlock as it should.

That new pulse solenoid is a Dorman product is it just cheap and need a dealer bought item, computer, etc.

My wife needs this to work, Country farm living, snow, hay field, we use it a lot for short periods. I've read a lot on this. Am I not waiting long enough? Jacked up or not it is not unlocking till I rotate to LOCK then return to AUTO, it is good to go till next time. HELP, LoL on comment but thanks in advance.

 

When you say you have tested with a vacuum tester I am assuming you mean you have tested that the lines will hold vacuum?

If you haven't tested to see if the solenoid is performing correctly (and are worried the dorman unit may not be working) you should check that as well. I don't remember the exact specs but the solenoid pulses one vacuum level for awhile to lock the hubs and another vacuum level for awhile to unlock the hubs.

If you have tested and made sure the solenoid is working then I would say you should grease your hubs. You can read about the procedure here from Guzzle's page. Even though the hubs are new, they may have been sitting on a shelf for awhile or what have you.

Baatzy

 

Thanks, the reply is great news , I had that hub out so many times, Is there a part in computer that sends a signal?

 

Did you change the O-Rings when the Hub was off?

 

Which O'ring? The vacuum hub came with new ones.

 

I did not replace that hub seal ,,,,But,, No leaks, can I make them unlock and lock with that mighty Vac? Test?

 

Yes. The first "pulse" will lock the hubs then the second "pulse" will unlock the hubs. You may have to roll the truck a few feet to get the hubs to fully engage/disengage. I haven't dealt with this in some time (I capped it off years ago after three failures and more money than I care to admit to throwing at it...so strike three and I was done). Here's an old post with the numbers (Post #16):

https://www.ford-trucks.com/forums/6...-number-2.html

 

I can't speak on the hubs as mine has had manual hubs on it since I got it but when I switch from 4WD to 2WD there is a short distance until the transfer case unlocks.

 

Thanks working at it now

 

Following to hear the solution.

 

My transfer case locks/unlocks immediately but my hubs can take a few feet to fully engage or disengage. When I had the ESOF hooked up to the hubs I would always go 3-4 feet in the opposite direction I was going when I engage or disengage to "rock" back and forth the get the hubs fully in or out of lock.

 

Update, I bought a new pulse solenoid just to have on hand for test today, tested with old one in place at solenoid ports as described in a previous post for the 40 second vacuum hold as you switch to 4wd, GOOD there, then tested as I went back to 2wd vacuum reads a little above 7" as should, BUT it only held 11 seconds still enough for the disengagement.

What I did discovered was when putting the new dorman part on it had same readings as for the 11 second hold back to 2wd mode.
So now best ever operation, tested 5 times on jacks and on ground after driving in field.

All along it either needed unplugged (solenoid) to reset(doubt this was case) or the die-electric grease I added. Problem solved!

Thanks FTE guys who sent in replies. Allen