Outer Limits 4x4 Board

i have a 98 model coily sierra and have been playing around with the idea of doing a diff swap with hilux/bundy diffs to be able to lift it more and get lockers front and rear. CBF due to money and the time it would take.

i have been looking around trying to get some info on swapping the diff centre from a leafy into the front so then i can fit a locker in (i already have one in the rear and would love one in the front)

the front ratio at the moment is 3.9

a few questions

1. what ratio is the rear in the coily?

2. has anyone done the diff centre swap before

3. would it go straight in? would the prop shaft of the coily fit the leafy centre or would one have to be fabricated to fit?

4. would anyone have a diff center that would suit?

cheers
andrew

if the splines are the same, you should be about to unbolt it all and swap the Ring gear and bolt the carrier in, if that makes sence, but you would have to check as i have been told the 1.3NT centers are diffrent to the WT, running the one ltr its a black hole for me, hope this helps

PS did you do i search im sure this was asked only a few weeks ago.

Don't forget that the late model front end has a high pinion centre and the earlier (NT/WT) have a low pinion. Your draglink that runs behind the diff is in the way. You'll need to re-engineer the steering while you're at it.

with some machining, it is possible to fit a Jimny airlocker in the front of a coiler IIRC.

Overkill has done this conversion.

If you are happy with your current diff gearing, that's the easiest option.

If you want lower diff gearing, then you need to look at fitting a whole leaf third member, but this requires the fitment of leaf steering knuckles and some other jiggerypokery, as pointed out by zookimal.

ok im looking at doing this soon..

basically as far as i understand.. i will need to cut steering nuckels out and replace with WT moddles (also get biger cv's) are wt and nt steering nuckles the same??? (also do caster correction whilst i am at it)

swap center to a rear NT (to use the bigger cv's and axels) and use WT steering set up???

i am going to be running custom arms with mine as well... need them anyways

or just do some machining of some parts and fit the Jimny one

and keep the little crappy cv's??? id rather get the stronger center and cv's in there... and all up it will proberbly cost ME less than a jimny locker..

WT housings are 35mm narrower per side than coiler.

Apparently basically WT cv's and coiler CV's are basically the same, but WT's can be readily upgraded to doubletough etc which you can't do with coilers because of the added width.

Making new inner axles will cost around $500-$600 for CrMo, then you can run DT CV's, CrMo inners and WT bearings etc on a coiler housing.

a jimny locker is the cost of the locker + machining.

Any other option is going to be $$$ if you want more strength than stock.

Steve.

sounds easyer to make some custom inner axles

exactly what machining is involved?

spamwell wrote:sounds easyer to make some custom inner axles

and it is, so long as stock CV's are strong enough for your application and youre happy with the gearing.

Steve.

PS- I've never done the machining so I can't advise, but it has been mentioned on here before.

got it done for me by 4play
low pinon front with 5.12s fits any locker i want but havent got lockers
rear diff gearing is 3.9s factory same as front

rear bolts in but front sterring and a few others bits need changingbut once its done you have enough gearing to run 33s very well
cost me nealry 3large though

so you have 5.12s in the front and 3.9s in the rear and somehow you think that is the same as the front? So your maths skills are equal to your communication skills.

factory coilys have 3.9s front and rear
thats the question he wanted answered

im running 5.12s front and rear you have to run the same gearing front and rear silly or your blow your diffs up or transfer case lol

Yeah I understand that but your post didn't say that and so far your tech explanations have been a little confusing so just wanted to clear it up

You spent $3K on you car to gear 33's on road, have 47:1 off road and open diffs?

Steve.

i couldnt do it and no one from victoria, suziworld or any other fab shop could do it f or me
so i had to pay top dollar.
ive spent 1000s on this girl to get her the way it is
around 3grand for the motor conversion
aound 1grand for the radiator and power steering
around 2grand for the suspension and body lift
around 3grand for the gearing

stupid hey!!! lol

coilys are more expensive to modify
should of bought a leafy lol

rustyzook
PS did you do i search im sure this was asked only a few weeks ago.

i did have a look on google, and here but didnt come up with much other than a bit on diff gearing and lockers.

i do remember seeing the thread on fitting the jimny air locker (months ago), but thought it would be cheaper and easier to swap out the centre if it went straight in. but nothing is ever that easy.

im happy with the strength it has, i am running 235s (28"). i dont plan on running any bigger rubber than a 31/32" in the future. i guess ill be looking into the jimny air locker set up.

thanks andrew

all the prices seem OK for what they are but the gearing thing still confuses me.

You've already put a gear drive case in, and with trail gear 6.5:1 gears in the case your road gearing would also have been spot on with the 33's - actually - even the speedo would have been right, you'd have had 92:1 crawl, and it would have cost 1/2 of what you've got in it now.

Just my opinion. The path you've taken is fine for road use, but 47:1 can't cut it in the bush.

Stock coiler crawl= 30:1
Your crawl with 33's = 47:1 - which has exactly corrected your big tyres (just like it has on road) but that's all. You're getting away with that gearing at the moment because you don't have lockers, but throw a locker or two and that gearing is going to be hurting you.

Beacuse of the 5.12 diffs, you can't really put transfer gears in the case because then you'll be up at over 4500rpm on cruise. The only option I can think of is 4.16 calmini - it won't change your road garing but give you a much happier 77:1 crawl - getting into the usable range IMHO, but then you're up to $4500 to sort the gearing and end up with a result comparable to just putting a 6.5:1 into a gear case.

That's my reasoning.

Like I said - you need to come out with some cars with more gearing to see how much easier it makes the car to drive. comparing a sierra to a patrol/cruiser in mud isn't really valid comparison.


Steve.

id love to see some zooks with trans gears to see the difference
most people are in sydney or qld or perth lol

plus i got told trans gears brake alot so i wasnt to keen on that idea where diff gears dont brake often

6.5s thats some super slow gearing
wouldnt of fixed my hi range to much either

but thanks for your input

Heaps more people in Vic running these gears. Suzuki 4WD Club of Victoria

wideaz wrote:id love to see some zooks with trans gears to see the difference
most people are in sydney or qld or perth lol

plus i got told trans gears brake alot so i wasnt to keen on that idea where diff gears dont brake often

6.5s thats some super slow gearing
wouldnt of fixed my hi range to much either

but thanks for your input

As Grimbo pointed out - there's heaps of cars with these gears in them in Vic and its a very long time since we've had any break, and the only breakages we had were with australian supplied gears.

Diff gears do break though - the rear 5.12 has a very small pinion and they are far from unbreakable, especially of the crush sleeve collapses. as for the front, your high pinion 3.9 was probably 75% stronger than the low pinion 5.12 you are now running.

6.5 transfer with 3.9 diffs and 33's isn't super slow at all - it's pretty sweet for victorian conditions, and you obviously didn't read my post at all - 6.5 transfer gears, on their own, will perfectly correct 33's on the highway with your existing 3.9 diff gears, so your high range would be the same as it is now.

Diff gears have their place, but they aren't enough to make a sierra usable in the bush with a big tyre on it.

Steve.

yes diff gears have thier place and they are enough to make a vehicle usable in the bush.

joeblow wrote:yes diff gears have thier place and they are enough to make a vehicle usable in the bush.

Yes, but you also have a 1.6, dual cases and an auto which makes a mighty big difference Will just diff gears help? Yes but reliable t-case gears such as those coming out of the USA are also a very cost effective option that should also be considered. Useable is not bad but enjoyable is much better

not talking about my vehicle, merely mentioning the 80% i've done with stock engines, transmissions and 31'3 or 33's. and yes, they are enjoyable too

wideaz wrote:id love to see some zooks with trans gears to see the difference
most people are in sydney or qld or perth lol

plus i got told trans gears brake alot so i wasnt to keen on that idea where diff gears dont brake often

6.5s thats some super slow gearing
wouldnt of fixed my hi range to much either

but thanks for your input

i go wheelin with a guy that has 6.5's there wicked!!!! its not the gears that break its the case , the case splits around the input and f#cks everything, thats fixable with a ring,

as for diff gears dont tell me there harder to break then TC gears, i have never done any TC gears but diffs, i know how to break a diff center


just a quick question, when you put the 5.12 vit centers in, did you take it out of the alloy housing??? if you havent mybe you shuld thing about it, ive seen what happens when the pinion rips out, just a helpful hint.

i got 4play to do the diffs so i dont know exactly what he did but there in and it works
been offroading many times and nothing has ever broken
yeah we can all brake diff centers by being total idiots but driving it properly shouldnt. unless you cut corners somewhere then it might brake

now that would be silly to leave ring and pinion in the alloy housing wouldn't it?.....

he didnt he did a great job thanks joe

wideaz wrote:i got 4play to do the diffs so i dont know exactly what he did but there in and it works
been offroading many times and nothing has ever broken
yeah we can all brake diff centers by being total idiots but driving it properly shouldnt. unless you cut corners somewhere then it might brake

mate im not having a go at you, im trying to help you!

and you dont have to be an idiot or cut corners to break stuff!! i think alot of the people in this site no matter what tech section will agree! stuff can were out and break! also diffs can break easy on rocks and alot of the stuff around here is rocky and i have broken a few centers in luxes and zooks, if they are gonna break they will!

as for the alloy housing insted of shovin it back and gettin all defensive you could have just checked and it could have saved you a new diff center if it wasent done prop! like a said they break in sierras!

http://www.outerlimits4x4.com/ftopic73445-0-asc-30.php

just have a quick look!