LOW WITHOUT CENTER DIFF LOCKED

Beast II · 04-04-03, 12:50 PM

At times, I'd like to be able to put the FZJ80 in low gear without the center diff locking automatically. Is there a way to do this ?

semlin · 04-04-03, 01:45 PM

umm, just curious but why?

you can start by getting a central differential lock switch if you don't already have one.

Wrench · 04-04-03, 02:50 PM

semlin is right. In order to do that you need a center diff lock switch installed in the dash. Very easy to do. 10 minutes tops to do. You can get one from sleeoffroad.com They are about $50.

Rogue · 04-04-03, 04:19 PM

The Center Diff Lock switch is only the first step to achieving an unlocked center diff in low range. You will then have to either remove a plug directly from the t-case, or do some modifications to your wiring. Both options have thier ups and downs.

It is not as easy as just installing a switch.

BTW, I have installed the switch and 10 minutes is a good estimate if you don't plan on removing any screws and just ripping the dash panel off, but plan on 20-30 minutes to do it right and make it nice.

I have not yet done the mod to run without the center diff locked in low. I haven't needed it, so haven't wasted time on it. If ever I do, I will do the wiring mods and leave the connector on the t-case so I don't get muddy goop in my connections.

Hope this helps...

Beowulf · 04-04-03, 05:00 PM

Matt,
The wiring mod mentioned by Rogue probably didn't make it from SOR over to this forum. CruiserDan posted the mod and it basically enables you to keep the plug on the Xfer case, keep the low-range tranny shift points, and allows the CDL switch to control the locking/unlocking.

Post back in this thread if you are interested in the details and he will post the details here on ih8mud.
-B-

cruiserdan · 04-04-03, 05:50 PM

The Wulf is correct...................... :bow:

*If you wanna know, I'll do it again.

*Don't ask until you put the switch in..... 8)

Rogue,

It's not a waste of time. Think of it as being one of maybe 3 or 4 people on the planet who even knew it could be done......

Knowledge is POWER............ :bow:

Rogue · 04-05-03, 11:47 AM

Okay Dan. I guess I should do it now just in case I need it later. Let me know what I need to do.

Thanks... :bow:

cruiserdan · 04-05-03, 04:08 PM

Rogue,

Ask and ye shall receive:

Remove the dead pedal and the left front sill plate. In the left kick panel you will find a Silver metal box. That is the ABS ECU. Remove it, and behind you will find a black plastic relay about the size of a cigarette pack. It says "transmission control relay" on it. That's what you are after. The EWD calls it the "center diff lock relay", same thing. Unplug the harness from it and take a terminal pick and remove the black wire with blue tracer from pin#7. Insulate the bare terminal to suit and then put everything else back where you found it. If you have the low 4 position swith at the transfer case unplugged, crawl under there and reconnect that as well.
What you have just accomplished is you have interrupted the signal from the transfer case that tells the lock ECU that you went to low range but you are still sending a signal to the transmission ECU telling it that you ARE in low range. Therefore the transmission will shift in the correct low range pattern. In addition you now have true manual control over center diff locking. It only locks when you tell it to without regard to transfer range selection.
Oh, I forgot the final step......Grab yerself a congratulatory #6 (but not an English one as you have just performed an electrical task, sorry Jim)

Regards.......Dan

pismojim · 04-05-03, 07:40 PM

Can anyone describe how the shift pattern changes from low to high range? &nbsp

oes it shift up/down sooner/later?

I got the switch in, and unplugged the plug a few years ago.

Rogue · 04-05-03, 07:55 PM

Thanks much Dan. :bow:

Maybe I will find some time in between classes this week to tear aprt my truck and put it back together even better than before.

Wish me luck. *I will need it. *What will likely happen is me posting in a few days with something like...

'I fried my electrical system and need to get a new ECU and entire elec. harness.' *Don't know if it is possible, but if it is I will manage it.

Later...

cruiserdan · 04-06-03, 05:33 AM

Jim,
The transmission shift points move up in low range, it also downshifts earlier. It is difficult to verbalize but very noticeable.
You can check it out like this:

Shift into low range and transmission in drive. Accererate moderately. The trans will go 1,2,3,od quite rapidly.
Stop and crawl underneath, plug the low 4 position switch back in and repeat the test. You will find that the gears hold for much longer, and when you let off the trans downshifts.

Give it a try...................

Regards....Dan

ParadiseCruiser · 04-06-03, 05:35 AM

Rogue -

Not to worry, it's a piece of cake - did it in my sleep

-R- (Previously res of Coquille)

thorvald · 04-06-03, 06:51 AM

mine came with it '91

Rogue · 04-06-03, 12:45 PM

See the problem is not installing the switch. It is messing with the wiring that worries me. I already have the switch in my dash. That was an easy one.

I will give the wiring mod a shot this week. If everything gets fried I will likely be importing a couple of New Mexicans to good ole' So. Oregon.

:bow:New Mexicans...

cruiserdan · 04-06-03, 01:07 PM

Rogue,

Ice down some Boddingtons, I'm on the way.........

Oh, S**t wait...Those are English.........

Make it Fat Tire.........

Rogue · 04-07-03, 09:37 AM

Modification finished.

It went well, but I did need to make a call to one of the Cruiser gods just to make sure I was doing it correctly. :bow:

After a quick test drive on the local logging trails the verdict is good. I like the feeling of the truck unlocked in low, and the shift pattern is great. No more BANG, BANG, BANG!

Any day that I get to work on the Cruiser is a good day. When the work is free and it makes the truck better, that is a great day.

Thanks for making today a great day Dan.

Beast II · 04-07-03, 09:57 AM

Gentlemen:

Thank you for all of the help. Question answered ? Now lets see if I can do it without electrocuting myself

Matt

erics_bruisers · 04-07-03, 10:42 AM

Watch out though -- I DID lose 2 of the same screw doing this -- the one that's at the top of the cigarette tray slider -- I couldn't recover them!

:dunno: :dunno: :dunno:

e

yomama · 04-07-03, 11:00 AM

Just a note that this is a good mod to have done. When I have to move my boat around I use low range, if it was locked it could create a binding type effect. When ever I put my boat in or out of the lake I always just use low and not locked, pretty impressive in low and unlocked, so far that is all I have needed. I was even pulling my boat out of a sandy launch where I was waiting for the guy ahead of me. He had a 12' boat trailered to his two wheel drive Chevy. He launched the boat, got back in his truck and proceeded to dig down in the sand, with nothing but a small trailer attached. He made some nice holes by the time he got it out of there, going back and forth. I thought "oh my god" I will never get my boat out of there, shoot, low range not locked, didn't even spin one wheel. I love my truck.....

Yomama

Beast II · 04-08-03, 09:03 AM

I'm always a bit apprehensive when dealing with the electrical system. I don't suppose anyone has pics of the wires ? I know its a long shot.

Matt

cruiserdan · 04-08-03, 09:19 AM

Matt,

It's not as hard as it sounds. Just get in there and take a peek. It will be quite evident. In other words, it hides in plain sight........................

Regards......Dan

Hltoppr · 04-08-03, 10:06 AM

:bow: Dan, do you know if the above instructions on the wiring and Tcase ecu are the same for the 91-92 models? Same wiring that is?

-H-

cruiserdan · 04-08-03, 11:14 AM

-H-,

You too can join the ranks of the un-locked low life...er ..range crowd. The ECU and the wire color be exactly the same...... 8)

The only difference is you didn't have to buy the switch.... :

&nbsp

unno if I like this...................my little secret is rapidly becoming public knowledge.............. :tear:

Hltoppr · 04-08-03, 12:47 PM

Nice! I'll probably do it tonight!

By the way, I lifted my first Boddington's this weekend, Darn good

It's $8.00 a four pack here in Flag. Yikes! :-/

-H-

cruiserdan · 04-08-03, 01:04 PM

-H-

You already had the switch. Let's see, 45.78 plus tax is 48.44...Divided by 8.00 equals .....um 6 of those lovely yellow packs.

How's that?

Chris_Geiger · 04-08-03, 04:01 PM

Here is a photo of the low lock plug. It is above the rear drive shaft.

cruiserdan · 04-08-03, 05:27 PM

That would be it.......The part you leave alone............

Chris_Geiger · 04-08-03, 07:55 PM

Quote:

That would be it.......The part you leave alone............

Here is the one you leave alone...

Beowulf · 04-09-03, 05:24 AM

Chris,
Is that a picture of the underside of your truck?

If yes, then please don't post any pics of that brand new xfer case skid plate unless you at least throw some mud on it. That truck obviously hasn't been out of the mall parking lots and Junk will get upset. We promised him that we would keep the "mudders" in line while he is out of touch this week.

-B-

Chris_Geiger · 04-10-03, 05:32 AM

Quote:

Chris,
Is that a picture of the underside of your truck?

If yes, then please don't post any pics of that brand new xfer case skid plate unless you at least throw some mud on it. That truck obviously hasn't been out of the mall parking lots and Junk will get upset. *We promised him that we would keep the "mudders" in line while he is out of touch this week. *

-B-

Actually the mall is one of the best places to find a new rig! By the looks of this one it's never been offroad in it's life. Well that's going to change. I was putting in a set of low profile drain plugs and changing the diff fluid and noticed how clean the diff's were so I shot a pic of them. The diffs and plug rings don't have a scratch on them