How to check if vacuum hub is engaging?

Discussion in 'Drivetrain Tech' started by Mattio, Sep 1, 2012.

  1. Mattio

    Mattio New Member

    I have a 1998 4x4 4.0L extended cab. I was told by a mechanic that the left front vacuum hub was not engaging. However, he was not a very trustworthy mechanic as I came to find (and I didn't give him any of my business) and I'm wondering how I can check this myself. Do I need to get all 4 wheels jacked up and put the truck in 4x4 to check this? If so, what should I be looking for?
  2. Freemans 00

    Freemans 00 Active Member

    either way theres a simple solution you can do yourself. Jack your truck up off the ground a place jack stands underneath the truck. Take your front 2 tires off the truck, now you will be looking at something like this...

    [​IMG]
    You will want to do exactly what they are doingh in the picture and take the center part off of the dust cap and then a White box will be inside that. Twist the white box apart and there will be a spring and a silver T clip. Take the silver Tclip out of the hub and reinstall this back in place. Now it will not lock so you will have to hold it in place, then put the center of the dust cap back on and reinstall your wheels back on and lower the truck to the ground.

    With removing this Tclip you will have a live axle like on the 01+ Rangers and you will not have to worry about the vacuum line 4x4 engagement system. There is many write ups and how to's if you search on google. How to fix 4x4 on a 1998-2000 Ford Ranger.
  3. djfllmn

    djfllmn ^^^ I am Mr. Clean!

    put the truck up on jack stands, start the truck and while still in park engage 4wd and put it in drive and see if all 4 wheels are spinning
  4. Mattio

    Mattio New Member

    Thanks, guys.

    Freemans, what exactly do you mean by this?:

  5. djfllmn

    djfllmn ^^^ I am Mr. Clean!

    the 01+ 4x4 rangers had no front hubs to lock/unlock...they were full time hubs...very reliable
  6. Freemans 00

    Freemans 00 Active Member

    Exactly what DJ just stated above. They only made a vacuum line 4x4 engagement system on 97-2000 I believe and it failed miserably thats why they changed it. I had this problem on my truck and it left me stranded a couple times.
  7. Mattio

    Mattio New Member

    So, the 01 Rangers are always in 4x4, you can't drive them in 2WD?
  8. djfllmn

    djfllmn ^^^ I am Mr. Clean!

    no you can drive them in 2wd but the front half shafts, diff, and driveshaft freewheeling, only thing you do when you hit 4wd is shifting the tcase
  9. Freemans 00

    Freemans 00 Active Member

    Its all mechanical in other words. With your current system when you shift into 4x4 from the switch it sends signal down to the vacuum line giving it a pulse to your hubs which goes to your transfer case. Well its something along those lines.
  10. Mattio

    Mattio New Member

    Cool, thanks guys!
  11. Bigcat84

    Bigcat84 New Member

    Is it safe to do this to a everyday driver???
  12. djfllmn

    djfllmn ^^^ I am Mr. Clean!

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