(5 minute) 7 pin mod also OD in Low mod in 5 minutes. 80 series fzj80 Lx450 (1 Viewer)

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GW Nugget

Do the best you can with what you have...
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Hello all... @Shoredreamer showed me this mod back in 2018 & now I wanted to share it with you.

I haven't seen this in any other threads so I thought to put it here.

The black wire with a blue stripe is the famous 7 pin mod wire. It is normally moddded on the left driver side floorboard panel, but the way I did it was by removing a connecter from the top of the transfer case. The yellow wire removed allows the transmission to go into OD overdrive while in Low.

Screenshot_20190713-200047.png


The connecter to remove is the #1 circled connecter.

20190713_184820.jpg


This diagram is for the smart folks to read.
Screenshot_20190713-200409.png


(My rig is a 1997 Lx450) = 95-97
93-94 might be a little different.

If you have not done a CDL switch mod you have to do this 1st before the 7 pin mod otherwise you wont be able to lock your center diff.
I did this vid back in 2015
(Best to watch at 1.25x speed)


Happy Trails to you....​
 
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The earlier models have OD in low 'from the factory'.

This was Tools R Us's preferred method way back in '06 or so, but that info may have gotten lost in the archives.
 
@GW Nugget i was told of this mod as the pin 7 pro mod haha. Still have the bookmark link in one of the Pin 7 threads on here. Welcome to Land Cruiser Owners On Line - http://www.lcool.org/technical/80_series/centre_diff.html I like this method cuz it’s reversible easily and the shift points in Low range locked and unlocked are much more enjoyable doing this mod vs doing the standard pin 7 at the kick panel, which retains that annoying super late shifting jerky 1st-2nd shift. This is especially true with 90-94 who don’t have 2nd gear start.
 
this one is new to me

i have a CDL switch but never got to the pin 7 mod. tell me why i want to do it this way, vs in the footwell? other than this is easier than wedging myself back into the footwell area

is the only change to the ECM getting a +12V signal on pin 9 the change to the shift points? i do have the 2nd start button.
 
I'm un aware of the pin 9 & the about shifting points. comments that @Shoredreamer mentioned.
I'm still learning... I myself am curious if the PWR but is effected also with shift points.
 
You're simply unplugging the low range position switch on the transfer case.
This was common on the FJ80 as they had the CDL dash switch and the transmission was not electronically controlled. It was a non-invasive way of getting manual control of the CDL in both low and high range.
On later FZJ80s the transmission shift points change when in low range, so it is somewhat beneficial to do the PIN 7 mod.
And if you're going into OD in low range, you really should be in high range.
 
...if you're going into OD in low range, you really should be in high range.
That depends on your tire size and/or gearing. With my setup my top cruising speed in low range is 30mph at 3000 rpm. In 3rd I'd be limited to around 25. The 5mph makes the difference between too slow and acceptable on dirt roads, without OD I'd be shifting in and out of high range all the time, which is annoying and gives less speed control. To each his own.
 
All good stuff guys, thanks.
Im running 4:88 minus 10% UD in High Tcase gear set so that comes to 5:36 so I like the little extra speed the OD gives like Spike wrote just above.
 
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I should add that both trucks also have the 3:1 low range t'case gears, so having O/D in low is a good thing.
 
I have a 93 with stock gearing and 285 tires, and I added the OEM CDL button. Based on this thread, it sounds like it would be better off doing the "T-case disconnect mod" rather than "7 pin mod"-- with the only down side to the T-disconnect mod that I may lose the special low range shift points that later 80's have (assuming this is even true for 93). If I want to turn off the OD I can use the OD switch.

Sound right?
 
Just trying to understand this "OD" mod (removal of the yellow wire post #1).....so by removing the yellow wire from the Tcase "4low" position switch, the transmission now will go into OD ? Is this correct? However, by removing this 4low mode feedback from the Tcase, the TCU doesn't know that you're in 4low and doesn't adjust the transmission shift points accordingly.

Or do I have this completely wrong?
 
Just trying to understand this "OD" mod (removal of the yellow wire post #1).....so by removing the yellow wire from the Tcase "4low" position switch, the transmission now will go into OD ? Is this correct? However, by removing this 4low mode feedback from the Tcase, the TCU doesn't know that you're in 4low and doesn't adjust the transmission shift points accordingly.

Or do I have this completely wrong?
I want to know too! After reading the lcool link, it appears you unplug the connector (labeled #1 in pic above) and wrap it up. This then allows manual control of the cdl and od while in low range. Black blue is for cdl control and yellow for od. To your point, I’m also not clear how this would change shift points, other than by disconnecting the yellow wire appears to trigger the transmission mapping (not tcase) to think it’s in high, which wouldn’t be a bad thing. All the benefits of the low gearing, without the jerky shift points. I’ll wait for an expert to chime in, but that’s how I’m tracking. It’d be easy enough to unplug and see what happens too.
 
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Just trying to understand this "OD" mod (removal of the yellow wire post #1).....so by removing the yellow wire from the Tcase "4low" position switch, the transmission now will go into OD ? Is this correct? However, by removing this 4low mode feedback from the Tcase, the TCU doesn't know that you're in 4low and doesn't adjust the transmission shift points accordingly.

Or do I have this completely wrong?
This is how I understand it. I’ve owned 93 and 94 models and they will shift into OD while in low range. This thread was written for the 95-97 models.

I’ve done a lot of wheeling and most of that rock crawling and never really felt the need to do the pin 7 mod. Then one day a couple years ago I decided I just had to have that pin 7 mod (still don’t know what got into me that day) so I clipped the appropriate wire in the drivers kick panel. All it did was give me low range in two wheel drive. I suppose that being able to disconnect front drive and maintain rear low range could come in handy in very tight quarters but I’ve never been unable to get out of a jam while in 4wheel drive. What we need is to be able to disconnect rear drive while maintaining front drive with diff locked.

I run air lockers so my experience may be different than those whose rigs are K294 equipped.

My 93 got killed last May. I’ll be building up a 96 as a replacement and I’m not so sure I’ll bother with this mod.
 
Just trying to understand this "OD" mod (removal of the yellow wire post #1).....so by removing the yellow wire from the Tcase "4low" position switch, the transmission now will go into OD ? Is this correct? However, by removing this 4low mode feedback from the Tcase, the TCU doesn't know that you're in 4low and doesn't adjust the transmission shift points accordingly.

Or do I have this completely wrong?

That sounds about right. Just crawl under the truck and unplug and try it out and you’ll see the difference.

Factory 93-97, Shift to LOW range:
-CDL locks
-ABS off
-transmission shifting changes (late shift/high rpm required out of 1st gear, No Overdrive)

CDL switch in dash changes:
-ability to now lock center diff in HIGH range. (CDL still can lock whenever shifting to LOW also)

Choose 1 below

Pin-7 mod at kickpanel relay changes:
-defeats the automatic center diff lock action when truck is shifted to LOW (requires the CDL dash switch to lock center diff, as that is now the only way the CDL can be controlled)

OR

Pin-7 Pro mod (tcase disconnect mod) changes:
-defeats the automatic center diff lock action when truck is shifted to LOW (requires the CDL dash switch to lock center diff, as that is now the only way the CDL can be controlled)
-when shifting to LOW, transmission “mapping” does not change from HIGH range therefore allowing OD and high range shift points.
 
When you guys unplug the connector, are you covering the male and female ends of the connector with anything to keep moisture/mud/dirt etc from getting in and corroding the pins or just leaving it?
 
That sounds about right. Just crawl under the truck and unplug and try it out and you’ll see the difference.

Factory 93-97, Shift to LOW range:
-CDL locks
-ABS off
-transmission shifting changes (late shift/high rpm required out of 1st gear, No Overdrive)

CDL switch in dash changes:
-ability to now lock center diff in HIGH range. (CDL still can lock whenever shifting to LOW also)

Choose 1 below

Pin-7 mod at kickpanel relay changes:
-defeats the automatic center diff lock action when truck is shifted to LOW (requires the CDL dash switch to lock center diff, as that is now the only way the CDL can be controlled)

OR

Pin-7 Pro mod (tcase disconnect mod) changes:
-defeats the automatic center diff lock action when truck is shifted to LOW (requires the CDL dash switch to lock center diff, as that is now the only way the CDL can be controlled)
-when shifting to LOW, transmission “mapping” does not change from HIGH range therefore allowing OD and high range shift points.

Thanks for the GREAT explanation. I have to agree, if the tranny shifted normally as if the Tcase is in High, when the Tcase is actually in Low, that'd be a huge improvement. My 2nd to 3rd shifting too delayed and jerky while in 4Low so I'm hoping this mod will eliminate this. Due to my 3:1 Tcase gearing, I have to drive with 2nd start engaged all the time.

Here's the question: why de-pin the yellow wire out of the 4low switch connector vs simply unplugging the whole thing all together? The statement below has be a little confused, I guess. If I have this question, others will too. I think this could be due to semantics but I wanted to confirm.

1694711142671.png
 
When you guys unplug the connector, are you covering the male and female ends of the connector with anything to keep moisture/mud/dirt etc from getting in and corroding the pins or just leaving it?

I'd be tempted to waterproof each half of the connector just as a preventative measure. Once could simply unscrew the switch out of the hole, and screw in the proper length of bolt, I suppose.
 
Thanks for the GREAT explanation. I have to agree, if the tranny shifted normally as if the Tcase is in High, when the Tcase is actually in Low, that'd be a huge improvement. My 2nd to 3rd shifting too delayed and jerky while in 4Low so I'm hoping this mod will eliminate this. Due to my 3:1 Tcase gearing, I have to drive with 2nd start engaged all the time.

Here's the question: why de-pin the yellow wire out of the 4low switch connector vs simply unplugging the whole thing all together? The statement below has be a little confused, I guess. If I have this question, others will too. I think this could be due to semantics but I wanted to confirm.

View attachment 3429314
Just unplug the connector and tape off both sides..
 
CDL switch in dash changes:
-ability to now lock center diff in HIGH range. (CDL still can lock whenever shifting to LOW also)
Partially correct. When you add a CDL switch to an FZJ80, the switch now controls CDL operation in both low and high range. It no longer will lock the CDL automatically when shifted to low range.
 

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