axle diff lock retro fit

[wayne80]

Hi, I have 2 land cruisers one is a manual box with diff locks and the other is an auto without the diff locks,I want to know if I can fit the diff locks into the non diff lock axle easily or is it better to swap the complete axles over?I know this sounds daft but I prefer the auto box and have provisionally sold the one with the manual gearbox,thanks Wayne.

 

[karl webster]

Did you buy the other then mate?

Good stuff. I have heard that all the wiring is in on the auto ready for the lockers.

Someone said recently that you can swap the diffs. Someone will come along soon who will know for sure

Karl

 

[wayne80]

Hi Karl, yes i have the white one as well ,my mrs loves it ! Chris is going to buy the red one minus diff locks,I bought a 2 sets of diff gaskets one locking diff,one open diff from milners but when you put one over another there are 2 holes that dont match up and ther must be some sort of cut out on the locking diff maybe for the actuator so as you said hopefully someone will reply,cheers Wayne.

 

[karl webster]

I had said that to someone and they said i was wrong.

Maybe you have just confirmed it.

Is chris letting me have that other one then

 

[karl webster]

Im not supprised she loved the white one.

It is very clean from the pics i saw

 

[Jon Wildsmith]

But of a tricky one that, the manual and auto have different diff ratios and putting the diffs from a manual into an auto isn't going to work out very well. Also, as you've noticed from the gaskets, the openings in the axle casing are different plus a couple of the studs. The none locking casing can be massaged to accept locking diffs but you'd be better off swapping whole axles and avoiding that. You could swap the gears as well as the axles but thats quite a lot of extra complication.

 

[wayne80]

I have hears that the ratios may different but one some sites people say that they are the same , I have access to auto diff locks if need be ,I will keep you posted when me and poor chris do the swap.

 

[Jon Wildsmith]

manual is 3.7, auto is 4.1, the only way they would be the same is if someone already swapped them

 

[Chris5-7chev]

"Poor Chris" ? I'll be mostly mashing the tea and sort of pointing at things and I did say the ratio's differ, (as I pointed at them!)

 

[callum]

at the back you need to grind out a bit of the mating surface to fit the diff and use longer studs. you'll also have to swap one of the shafts so you have the long splines.

at the front you'll need to drill and tap new holes for studs, as you've found out, and possibly add a bit of weld to the diff casing and grind back to increase the size of the mating surface.

you'll also need to add a diff lock ecu and run some new cabling. Depending where your truck is from, you'll either just need the looms from axle to car, or need the loom from axle to car and to make a new bit of loom from rear of car to front.

there are write ups on ih8mud with pictures on this subject.

 

[Toby]

Hi Wayne,

As Jon says above, whilst you'll get away with putting auto 4.1 ratio diffs into a manual if you don't want high speed cruising or you're fitting taller tyres, manual 3.7 ratio diffs in an auto won't work at all well - you'll probably end up overheating the transmission.

AFAIK it breaks down like this, for turbo diesel 80s at least:

All euro spec manual 80s came with 3.7 ratio diffs.
All auto 80s worldwide came with 4.1 ratio diffs.
SOME Australian and 'general area' spec manual 80s had 4.1s, possibly some JDM spec had these too.

If you're lucky enough to find that you're manual is an import with 4.1s then swap the complete axles over.

If not and you're going to be extreme off-roading you might ultimately be better off going for ARB air-lockers in the unlockered car, if you can find someone who really knows what they are doing to fit them (poor fitment seems to be the cause of almost all airlocker problems).

Hope this helps,
Toby
1990 HDJ80
1994 HDJ80

 

[wayne80]

Hi everyone , thanks for all the replies,the car I am fitting the diff locks into is a 1995 24v auto jap import,I have noticed that there is a wiring plug underneath the passenger rear floor,maybe this is the rear diff lock wiring?as for the gear ratios I will have to jack the cruisers up and work out what they are ,back to the wiring I am assuming that it if the wiring harness is fitted its just a matter of plugging in the switch/ecu and possibly fitting relays/fuses and hopefully job done,thanks once again Wayne.http: