Need Help 3.9 Ratio Diff From NM Pajero Into ND Diff

[paj302]

Wanting to know wether or not a 3.9 ratio center from a later gen 3 nm pajero (Came out in 5sp auto 3.2d) can be fitted into a ND pajero diff housing, Wanting to lower the revs a bit.

[NJV6]

No, but there may be other options for you or do you already have the 4.6 gears?

Or try 33's!

[paj302]

currently running 33's at moment, have a 4.85 diff

[bakerboy]

ill swap u my 4.625s for ur 4.85s

[paj302]

How many revs at 100km's will 4.625 gears alter from the current 4.85's.


Are 3.9 crown and pinion from nm front diff interchangeable to nf rear 4.875 crown and pinion as same size housing and still 28 spline

[bakerboy]

4.625 wont lower them that much, i runn 32"s and at 100 they sit about 2700odd rpm

[Bitsamissin]

How many revs at 100km's will 4.625 gears alter from the current 4.85's.


Are 3.9 crown and pinion from nm front diff interchangeable to nf rear 4.875 crown and pinion as same size housing and still 28 spline

No................4.625 is the lowest you can go with your current diffs.
NF/NG
front = 8" low pinion
rear = 9"
NM/NP
front = 8" high pinion
rear = 9.5"

[paj302]

what would i have to do to alter diffs so can run later model 3.9 ratio diff in 87 pajero, would i have to get one from nm altered to suit solid axle.

[Bitsamissin]

Do you actually have a 3.0V6 coil sprung rear ?
If so this would be your only option I would think.
You would have to swap out your front diff with a 8" high pinion from a Gen 3 no-one has actually done this to my knowledge. A Gen 2 8" high pinion is a bolt in job but you have to remove the front dog clutch actuator and plug the hole of course leaving the dog clutch enaged.
I don't know if the Gen 3 front diff is actually the same externally for a bolt in fit but the internals are the same as a Gen 2.
The cheapest way would be if the Gen 3 diff will bolt straight in with the 3.9 ratio.
The rear is the most complicated you would have to swap in a live axle 3.5 V6 9.5" rear axle assembly - has been done before, gives slightly wider track and only needs the tailshaft to be modified.
Then a 3.9 C&P installed but again no-one has actually done this to my knowledge. The Gen 2 9.5" diff and Gen 3 9.5" diffs share the same centres but there's no guarantee that the C&P are interchangeable - part no's suggest they are.
It's a lot of work and will cost $$$$ even sourcing parts from the wreckers and if the rear 3.9 C&P doesn't work in the 9.5" live axle then your stuffed.
I'm trying to work out why you would won't a 3.9 ratio behind a 3.0 V6 it would kill driveability and make it a pig to drive - I would just try bigger tyres first and see how you go.

[paj302]

thanks, will chase up rear diff shortly, actually only running 2wd with 302 v8 ford motor, thats why chasing 3.9 ratio rear end.

[Bitsamissin]

Oh I see now.
Maybe a better option is the current Triton GLX 4x4 Triton which has a 3.917 ratio but it is leaf springs. This is also a 31 spline 9.5" rear diff.
The Triton 8" high pinion front diff should be a bolt in fit as well if you want 4x4 as well.

[paj302]

thanks, what dimensions are they on the ml triton glx diff, ie total width and leaf mount spacings etc in comparison to nd pajero

[Old colt]

If you take a look at the L200 of a similar production year you will find the 4.22 ratio that will go in your Montero. There is also a 3.9 available but probably just in the smaller axles.

This will not be a whole axle swap you will need to do just the 3rd member.

[SiKnEsS]

the mitsi scorpion also run the same diff centre, u can get them in a 3.36 and a 3.9 if u look hard enough, and they r a direct bolt in, as i used to use gen 1 pajero centres in my race cars for the 4.6 ratio lol

[paj302]

So does the 4.22 ratio triton diff centre bolt straight into housing, does the 4.22 ratio come from 2wd or 4wd, is it a lsd

[Old colt]

The rear center should swap right in as well as the front. The front will be a low pinion as your truck is.
The 4.22 are common in the 4WD, 3.9 is found more in 2WD and might be hard to find in the 9".

The LSD is very easy to swap from one gearset to another. It is about ½ hour job once the unit is on a bench. You only need to reset the backlash of the ring gear. Well it may take an hour if you have not done it before

I think you would be better off with 4.22 rather than 3.9 in your truck.