Pin 7 mod /Lo sensor removal

Julian

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Sep 9, 2012
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Having read the post in the 80 section about pin 7 mod, I thought I should post my findings on the 100 series
If you do the lo-sensor mod on a 98-2000 100 series diesel, you loose the ability to lock the center diff, this in turn means you can't lock the rear diff
Pin 7 would seem the only way to stop the center diff locking when in lo-range on the early 100 series diesels, you just have to put up with the shift pattern. It had me and JulianV scratching heads for a bit
 

Steve Wright

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Julian said:
Having read the post in the 80 section about pin 7 mod, I thought I should post my findings on the 100 series
If you do the lo-sensor mod on a 98-2000 100 series diesel, you loose the ability to lock the center diff, this in turn means you can't lock the rear diff
Pin 7 would seem the only way to stop the center diff locking when in lo-range on the early 100 series diesels, you just have to put up with the shift pattern. It had me and JulianV scratching heads for a bit

Julian

I am not really sure what you are trying to say about the "pin 7" mod, but I did this on mine 5 years ago,and every thing works as it should, and the main point is to be able select diff lock in high range.

Steve
 

Julian

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Sorry should make it a little clearer, if your 100 series automatically locks the center diff when you engage low range and you don't want it to do the pin 7 mod, rather than unplugging the low range sensor from the top of the transfer box.
 

Steve Wright

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Julian said:
Sorry should make it a little clearer, if your 100 series automatically locks the center diff when you engage low range and you don't want it to do the pin 7 mod, rather than unplugging the low range sensor from the top of the transfer box.
Hi Again

As far as can remember, it did not automatically select the diff when you went to Lo, but would you could only turn the diff lock on when in Lo, so the mod made it possible to turn the diff on in high range as well.

The only thing that is a shame that the rear diff only works in low range !

Steve
 
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Jon Wildsmith

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Mine doesn't automaticaly lock the centre diff in low, I have a button on the dash for that which works in high or low. I do get the stupid shift pattern in low though and haven't got round to disconnecting the low sensor so I just use the 2nd start button unless I want to crawl.
 

Julian

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I believe the auto locking centre diff is for early diesel cars that don't have traction control etc.
 

Julian

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John, yes I have a center diff lock switch.
Stock set up is
High range - switch works locking and un locking diff,
low range - switch does nothing, center diff locked all the time

when I disconnected the low sensor from the 'box, I could use low range without automatically locking the center diff, but the switch did not work ie I could not lock the diff at all in either high or low range

Pin 7 mod allows me to use the center diff lock switch in either high or low range, indecently it also allows me to ock the rear diff in high range, not sure why I would ever want too

make sense?
 

Jon Wildsmith

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Got it. Not sure it makes sense though. You sure you disconnected the right plug on the back of the transfer box? Seems strange that you have control in high, yet with the plug disconnected so it thinks it's in high still you lose control? That's what would happen if you disconnected the CDL plug which is in the 1 o'clock position on the front of the transfer box as opposed to the low sensor plug in the 1 o'clock position on the rear of the box ...
 

Jon Wildsmith

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I think you have something odd / not right going on there Julian. The low sense switch is just a make / break switch so disconnected is electricaly the same as being in high. Shame it sounds like you're not coming to Lincomb because it would have been interesting to see what's going on there. The centre diff lock 'ECU' is just a box of 3 relays so it has no magical properties :lol:
 

Andy Harvey

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Mar 6, 2010
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Julian said:
John, yes I have a center diff lock switch.
Stock set up is
High range - switch works locking and un locking diff,
low range - switch does nothing, center diff locked all the time

when I disconnected the low sensor from the 'box, I could use low range without automatically locking the center diff, but the switch did not work ie I could not lock the diff at all in either high or low range

Pin 7 mod allows me to use the center diff lock switch in either high or low range, indecently it also allows me to ock the rear diff in high range, not sure why I would ever want too

make sense?
Just to show that the Diesel lump is so damn good that it doesn't even need to be in low range off road - quite a neat trick to embarass owners of less capable motors.

Just had min off road at the weekend on my new Cooper STs and I have to say the lack of being able to be in low range without centre diff locked was a bit of a pain as to be honest it didn't really need it. The Coopers grabbed the mud pretty well and that low down grunt and the fact that I didn't use the loud pedal too hard meant that I never came close to losing grip either in Mud, on gravel or on muddy ascents. I'm a bit of a convert to the 100, I thought it would be far inferior to my old 80 but to be honest I didn't really notice any difference apart from being more comfortable, quieter and the Stereo was better. Even got to prove the front camera was worth having as well. Plus I was a bit more circumspect about going too near anything that might scratch the nice shiny paintwork :lol:
 

Andy Harvey

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Yes they are quite big. didn't have any problems where I went with it but it is an old quarry and most of the runs are quite open. It does make yo more aware of the bodywork though and forces you to drive a bit tidier.
 

Jon Wildsmith

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Julian said:
John, in the end I had to go up to see Julian to sort it out. Defiantly the low sensor pulled
Are you talking about the pin 7 mod where you just remove pin 7, or did you also patch the diff lock ECU to bypass the low range blocking diode? I think you must have done more than removing pin 7 if you can lock the rear diff in high? Also, if you lock centre diff in high range, do you get the low range aggressive shift pattern? I'm just curious about this now you've given us a puzzle to solve :mrgreen:
 

Julian

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John it was a bit of mission,

started off with me doing pin 7 thats all, I lost the ability to lock center diff in either high or Low (This turned out to be a broken CDL sensor)

Put pin 7 back together (initial thought was that I had this wrong)

Went up to Julian's to find that my CDL actuator was full or crap and needed a clean out, he pulled out the Low sensor and it didn't work correctly and I can't remember why :oops:

Went back to Julian's we fixed the CDL sensor, then with low sensor out tried to use low range without the auto CDL, no go. Plugged the low sensor back in everything back to normal. Did the pin 7 mod now working as described. Did some further testing to find that with CDL in high I can lock the rear diff as well

Oh yes, I do have a 2nd start button.
On the crazy shift pattern in low range, I did find it pretty usefull on long accents, didn't want to loose momentum changing gear
 

Jon Wildsmith

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To complete the picture Julian, do you get the crazy shift pattern in high if you lock the centre diff? Possibly not something you've been able to test / notice :)

Disconnecting the Low range sensor you should still be able to lock the centre diff but not the rear diff. With just pin 7 removed you should have manual control of CDL but still only be able to lock the rear diff in low range. You have something special Julian :)

If you disconnected the low range sensor, disconnected pin 7 and piggy back the removed pin/wire to pin 6 you'd have manual control of CDL and be able to lock the rear diff both in high or low. If your low range sensor is still connected then I'm guessing the removed pin 7 wire is now connected to something else that goes positive when the centre diff is locked? I can see a couple of ways of doing that, e.g. a relay wired to the CDL sensor (pin 7 needs +ve, CDL sensor switches to gnd) or by patching pin 6 directly into the rear diff lock ECU pin 8 instead of the low range sensor input.

I quite like the crazy shift pattern / 2nd start combination for flexibility i.e. being able to crawl at quite high revs and know it will stay there or use 2nd start to lose the crazy revs. I'll have to have a think about what I want now you've made me think about the options though :D I might just connect my pin 7 wire through a switch to +ve seeing as I don't need to worry about the rear diff ECU :think:
 

Julian

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John, during a moment of clarity at 3am this morning, I remembered what happened
You are correct, with the low sensor disconnected I did have switchable CDL in both high and low range, but I lost the ability to lock the rear diff in either range.
With the pin 7 just disconnected, I got the ability to have switchable CDL and the ability to lock the rear diff in low range and strangely high range without any further mods :o
Also in answer to your other question, I don't get the crazy shift pattern in high range with the CDL
One day I would like to put in Rodney's valve body and lock up kit, with that and the pin 7 mod, I think I will have pretty much have all the bases covered from the gearbox perspective, the only other thing I have toyed with is the ABS mod I have read about
 
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