Confused about when to used CDL

Discussion in '80-Series Tech' started by 92FJ, Jul 7, 2005.

  1. 92FJ

    92FJ

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    Im confused about when to use the CDL as I got into a small arguement with several people about this issue. Can I get a real, factual explanation? Thanks
     
  2. Romer

    Romer fatherofdaughterofromer Moderator

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    If you go up to the FAQ and read the link Diffs for Dummies, that will explain how it works.

    Don't use it on dry pavement.
    Don't use it at high speeds
    Use it when you are off road or bad weather

    It takes you from AWD where the front and rear axles can slip from each other to 4WD where the axles are locked together.
     
  3. OZCAL

    OZCAL

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    There is a steep incline where the deep sand beach becomes the pavement. Generally requires speed to get through without bogging. But there is a "curb" at the start of the pavement, followed by a lot of big dips/bumps in the pavement. Rather than hitting the curb and bumps at twenty and spilling my soda pop, I lock the center diff and go slow, but fast enough to bounce the front end up the curb, and let the front wheels pull the 80 smoothly up the ramp where otherwise the rear wheels might have spun in a slow unlocked approach. No spills.
    David
     
  4. MaddBaggins

    MaddBaggins Remember the KnightRider!

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    Offroading. I did the pin 7 mod, so when I wheel I use 4 lo unlocked. After a couple attempts at something, then I lock the center. :cheers:
     
  5. OZCAL

    OZCAL

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    For me, it's a couple of attempts, get out of the truck and dig out, then lock the center :doh: .

    David
     
  6. jcj_78FJ40

    jcj_78FJ40

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    Having a 92, you probably have the non-viscous transfer case, which is good. This TC in normal mode (unlocked) will allow the drive shafts to turn independently. This keeps stress off of the drive train while turning on hard surfaces. The down side, you can get stuck if only 1 wheel loses traction (unless you have diff lockers).

    With the TC locked, the drive shafts are locked together. This will keep you going as long as 2 wheels don’t lose traction. This should be used off road or in snow, which will allow the wheels to slip while you are turning.
     
  7. Josh83

    Josh83

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    A general rule: If you were in a traditional 4wd with a 2wd mode, and you are somewhere that you would put that into 4wd, lock your center diff.
     
  8. Safado

    Safado

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    Why not...?
     
  9. Doc

    Doc

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    I think the owners manual says to not go over 30-35 with the diff locked. Partially, I'm sure that's due to the fact that ordinarily the 93 on up's couldn't lock the c-diff until they shifted into low anyway.
     
  10. OZCAL

    OZCAL

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    Or are they worried about people who don't understand that the ABS has turned off?
     
  11. e9999

    e9999 You want to do what...? Moderator

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    I guess the simplest way to put it would be that it's the first step to implement if you think you are going to have -or are having- trouble. I have been amazed at what I could go over with just the CD locked (no end diffs locked yet). This system is really effective! Better, I've been able to get through some spots with nothing locked that gave trouble to regular locked 4x4s.
    Cruizahs rule!
     
  12. nyk438

    nyk438

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    I use it when I have to throw it in 4LO, still need to do pin7 mod, never actually push the button to turn it on when I can't make it up something in 4HI or AWD. I've noticed with froading an unlocked truck you gotta get a running start sometimes works for me.
     
  13. Zen Dude

    Zen Dude

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    Does the pin 7 mod just turn off the center diff lock when your in 4LO?
     
  14. Rookie2

    Rookie2

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    No. Under normal drive mode, the CDL is not locked. So the pin 7 mod does not turn off something that wasn't turned on to begin with. The pin 7 interupts the signal that tells the transfer case to lock when you switching to 4 lo, so you can to drive in 4-lo without the center diff. automatically locking.
     
  15. Hants

    Hants

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    I'm just learning the flexability of the truck, and what to use in which situations.

    Locking the center in High or Low WILL cause driveline windup on hard (high-traction) surfaces. (Tried it one time on in a parking lot, and forgot until I tried to turn into a parking spot -- felt the driveline windup, and almost took out the Miata in the next spot :eek: :rolleyes: )

    Leaving the center unlocked (even in Low) allows tighter turning.

    I leave everything unlocked, except as below:

    Obvious trail damage from other people spinning tires: lock C or C/R (to prevent further damage)

    Significant risk of lifting a tire: Lock C

    Significant risk of crossed-up-suspension (and 2 wheel lift): lock C/R

    I want to show off and tractor up a slippery cliff: lock-em-all

    Before I got the truck, I thought I would practice driving without the lockers at all to "improve" my skill... that lasted until I got the center to lock correctly (earlier thread). Now, I find it's just too easy to push-the-button/turn-the-dial before ever spinning :eek:
     
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