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Just did 7-pin, is this right?

Discussion in '80-Series Tech' started by sonoranfun, Aug 11, 2005.

  1. sonoranfun

    sonoranfun

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    I just did the seven pin mod and I had some issues. I got things taken care of in time but I took out the blue with black larger wire first. Anyway, I fixed it so now here's my issue and I wanna know if this is right.

    After doing it I went to make sure that the CD wasn't locked in 4low. What I found was that it didn't seem like there was as much torque in 4low, so I put it in 4high like normal and put the gas half down, then I put it back in 4low and did the same thing. It seems to take off just as fast both times but in 4low is shifted out of 1st WAY sooner.

    Anyway it feels odd but does this sound right? Maybe it was just cause the CDL wasn't locked it was faster? I don't know, I'm clueless here and just doing what IH8MUD tells me:)

    So, is this all right?
     
  2. sonoranfun

    sonoranfun

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  3. sjcruiser

    sjcruiser

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    I could idling up my sloped driveway if I'm in 4Lo, while couldn't do so in 4Hi - just giving you some ideas
     
  4. MaddBaggins

    MaddBaggins Remember the KnightRider!

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    After I did my pin 7 mod this is what I got... I still feel torquey in 4lo and it doesn't shift to 2nd until somewhere above 2k rpm. I don't remember exactly what rpm it shifts at, just that b4 it finally does I am thinking "damn, whens it gonna shift" If you wanna get together and compare shift points come to the meet tomorrow nite. later
     
  5. spressomon

    spressomon glutton Moderator

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    I didn't notice any difference regarding the shift rpm points before or after the 7-pin mod on my 100. However I really like being able to lock the CD in lo or hi. And I just did a mod so that I can run the factory rear e-locker in lo or hi too...
     
  6. Rich

    Rich

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    On a 80 LC removing pin 7 does not alter the shift points.
     
  7. kemasa

    kemasa

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    Pin 7 mod and shift points

    That is true, but what it does is to retain the shift pattern difference when in low, which is lost when you pull the connector from the transfer case, which is the other means of disabling the cdl when in low.

    By default, on a 80 series LC, at least on my 93, there is a different shift pattern when in high vs. low. The low pattern holds first gear a lot longer.
     
  8. turbocruiser

    turbocruiser SILVER Star

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    Fellas, let me take this thread through a slight stray if you do not mind. I have not completely confirmed this but I do not think my rig has the pin 7 mod, ..., yet. The last time I went out wheeling (slaughterhouse gulch) I noticed that in 4-low the rig would really resist shifting to second gear - the rpms would hover around 2500 to 3000 before it would shift and when it did shift it would do so with a small sudden lurch. This occured whether the gear selector stick was in second or in drive but not when it was in low (of course it did not shift to second in low and i did not drive fast enough in low to require any shifting anyway). I had never noticed that before but then again the terrain through the gulch was different from my typical snow/sand/slop type runs where I rarely wheeled with low selected. Is this normal? Thanks. :cheers:
     
  9. kemasa

    kemasa

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    Yes, that is the normail low shift pattern.

    The only way you would not have the normal low shiift pattern is if you removed the connector from the transfer case or otherwised modiifed the wiring such that it would not know that it was in low.

    There are two basic mods to not have the vehicle lock the center diff in low. The first is to disconnect a plug at the transfer case, but this affects the low shifting pattern. The second is the pin 7 mod, which retains the low shift pattern, but does not lock the center diff.
     
  10. turbocruiser

    turbocruiser SILVER Star

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    Great, good to know thanks. So am I understanding right that if as soon as you shift into 4 low and the CDL light on the dash also automatically comes on (as mine does) that the pin 7 mod has NOT been done? Thanks again. :cheers:
     
  11. kemasa

    kemasa

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    Correct, if you go into low and the CDL comes on, then neither mod has been done.

    I prefer the pin 7 mod since you don't have to protect the connector and the plug from water, etc. as it is inside the vehilce. At some point I want to find the control for the shift pattern and put a switch in to control that. I found it on the electrical diagram once, but finding the actual location in the vehicle is a different story, plus for the most part it does not matter, which makes it easy to ignore for now :).
     
  12. turbocruiser

    turbocruiser SILVER Star

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    Again, great, good to know, and thanks. My CDL light comes on as soon as I shift into 4 low so my rig has not had the pin 7 mod, ..., yet. Also it comes on whether in 4 high or 4 low if I hit the CDL switch so I can confirm that that CDL switch works. Apparently the only thing I cannot do is go into 4 low and leave the CDL off. Also, apparently the only way to lock the CDL when in 4 low IF the pin 7 mod has been done is by hitting the CDL switch after shifting to 4 low. Thanks again, I appreciate it. :cheers:
     
  13. kemasa

    kemasa

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    Yes, adding the CDL switch allows you to lock the center diff in high, but will not have any other effect without doing somethng else, like one of the mods.

    Yes, you are correct you do need the CDL switch before doing either mod since otherwise you will not be able to lock the center diff at all. It is nice to be able to go into low without the center diff locked for moving a trailer and other such things.

    Since you have the switch, you can do the mod and the only real difference is that you would need to push the switch if you want the center diff locked when you go into low. I have driven in low without the center diff locked since I only needed the lower gears and with all wheel drive, it is was good enough (dirt road which was steep, nut traction was not really an issue).
     
  14. turbocruiser

    turbocruiser SILVER Star

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    Great summary, great to know, thanks again. I think I will do the pin 7 mod, not necessarily for towing a trailer but just because it gives you one other option. Thanks again. :cheers:
     
  15. tarbe

    tarbe

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    The CDL/Pin 7 mod is also a great mod to have if you find yourself in serious mud. It can be tough to get enough wheel speed to clean ATs in low range. With this mod, you can lock her up in high range and really fling the mud!

    Not that I would ever do that....IH8Mud!
     
  16. kemasa

    kemasa

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    You are welcome.

    Having the options is the reason why I did it too. It does not take long to do it either. I actually pulled the plug on the transfer case first, then found out about the pin 7 mod and did that and put the plug back in.

    The instructions are pretty good and straight forward.
     
  17. MaddBaggins

    MaddBaggins Remember the KnightRider!

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    Sonoranfun, went into Chiva falls today and paid attention to my shift point.
    4lo CD unlocked, it shifted into 2nd around 2500-2600 rpms with a quick, almost lurch into 2nd. That's how it's worked since I did the mod. Hope that helps :cheers:
     
  18. sonoranfun

    sonoranfun

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    Thanks Madd.... Wanted to meet up with you guys the other day but I've been sleeping like crap! Then I get up late and find myself in a rush to get anything done before the sun goes down. Please let me know next time you all do something as I'd really like to meet up with you all.

    As for my shifting, I took closer note today and it seems fine, sort of seemed a little harsh to me and then when slowing it sort of shifts back into 1st and you can feel something around 5mph. Otherwise it seemed fine though, thanks for keeping an eye out for me!
     
  19. JimmyK

    JimmyK

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    Probably an ignorant question but please bare with me I am a noob.

    Once you remove the 7th pin from the harness do you wire it up with a button up top so you can enable it and disable it at will? Because having your CD locked can't be good for road driving correct?
     
  20. tarbe

    tarbe

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    You do the pin 7 mod in conjuction with adding a center diff lock switch.

    The center diff is only on when you depress the CDL switch.

    Pin 7 allows you to run low range without the center diff locked, or to lock the center diff in high range.

    If you do pin 7 without a CDL switch, you will never have the center diff locked (or your front/rear lockers if you have them).