SJ413 - vitara diff swap or transfer case?

[wayfastwhitee]

Hey,
I have a 1987 SJ413 with 31s. About six months ago i bought two front vitara 5.12 diff heads, crush sleeve, pinion nut, oil seal and the retaining can kit from lowrange offroad. So i'm all set to do the swap and its just been a matter of finding the time do to it. Now that i've got the time to do it, i've been talking to people and they all seem to think that i'd be better off ditching the diffs and just going for a SJ410 transfer case as the reduction isn't so big. The main concern for me now is that the truck is my daily driver and so i still want to be able to use it on 50, 80 and 100kmh roads without it reving its head off; but be able to take it on trails and have some decent reduction as its gearings pretty crap at the moment with standard transfer case/diff.
any oppinions on what i should go for would be very much apprecitaed
thanks,
Tom
.

[UBZ]

5.12 diffs are suited to a 33" tyre but won't help your low range.

410 transfer is approx 12% reduction in high but not much in Low , so will help your on road driving but not really help low range offroad.

your best opion is an aftermarket transfer gear set, either 4.16 or 4.9 depending on how low you want.

have a look here for options

http://www.lowrangeoffroad.com

[wayfastwhitee]

Ok, thanks for your reply. The only thing i'm unsure of is how you said the SJ410 transfer case doesn't help low range much; for example calmini sells their 4.16 kit and state that it has 12.2% high range reduction and 83.6% low range reduction. Is 83.6% not very big for low range reduction?
I know that kits like the 6.5 have over 200% reduction, but i'm just not sure as to how relative that is; if 200% reduction would be suitable for running for example 35s, is that not comparitive to having 83% reduction with 31s?

[UBZ]

a 410 case only gives you approx 10% reduction in low from stock .

I run a 4.16 case in my 413 with 31's and a very revvy gti engine.
can idle about in 2nd low most places and don't have to change into high range unless I really want to go fast.

great for NZ conditions .

a 6.5 case is much lower , good for rock crawling ( super slow stuff) but would have to change to high for fast mud sections etc.

if I did it agian I would go with a 4.9 case as I'd like 1 more lower gear as it would suit my slow driving style a little better

[strx7]

important note - Flat decks use lower gear transfer low ratio than hardtops do......

so you cant just go claiming SJ410 vs SJ413 you need to stipulate Hardtop or Flatdeck aswell.

[wayfastwhitee]

Ok cool things are starting to get cleared up for me now. I didn't realize that there was any substantial difference between the SJ410 transfer case gears and a 4.16 calmini kit.
So to ask one more very uneducated question;
The stats that i've looked up state that an SJ410 has:
High: 1.58
Low: 2.51
Now the way that i assumed it worked (in order to be the same as a 4.16 is that its 1.58 + 2.51 = 4.09.
But that now can't make sense if you say that there is only 10% reduction in SJ410 low range compared to 83% with the 4.16.
So is the 4.16 calmini meaning that it is 4.16:1 when in low range?
Thanks for your help, its probably all quite basic logic, i just haven't fully got my head around it yet!

[UBZ]

important note - Flat decks use lower gear transfer low ratio than hardtops do......

so you cant just go claiming SJ410 vs SJ413 you need to stipulate Hardtop or Flatdeck aswell.

the flat deck transfer or pre 84 410 softtop or hardtop is not compatible in a 413 without running hybrid 410/413 drive shalfts as the flanges on the transfer are different to the 413 and cannot be swapped with 413 ones as the spline is different .
the difference in low range is marginal as well.
If your going to the effort of re-gearing the best option IMHO is an aftermarket gearset .

4.16 or 4.9 or 5.1 or 6.5 refers to the low range ratio in an aftermarket gearset .

[Rotazuk]

This may help explain what is going on .



Note the 413/samurai ratios and the 410 ratios , the 410 ratio's are the 1984 410 ratio's . The earlier t/cases are very similar in final ratio but use different gears to get them and can't be made into a 4.16 case . A rocklobster is a 4.16 t/case ( as you guessed this refers to the ratio in low range ) .

Short answer a 4.16 t/case would be a good option but it does not correct a speedo error from larger tires ( minor issue )

Std 413 high is 1.409 = (41/44) x (62/41)
Std 410 high is 1.58 = (53/31) x (49/53)
12% change (1.58-1.409)/1.409

Std 413 low (41/440x(56/23) = 2.26
Std 410 low (53/31)x(47/32) = 2.509
(2.509-2.26)/2.26 = 11% change

4.16 t/case will have 410 low gears so a 12% reduction in high and 4.16 gears in low so an 83% reduction in low . And yes I was killing time


Chris

[wayfastwhitee]

That diagram is so well done, definitely cleared things up for me. Its awesome to know how the actual ratios are calculated other than just doing the whole rotate and count thing.

Thats the other problem, sourcing a 1984 SJ410 transfer case is going to be difficult. I rang around about ten different wreckers yesterday and no one had anything; except for one in pretty rough looking condition.
Its just a matter of keep searching.. or spend USD $525 + shipping on gears haha

[Rotazuk]

http://www.trailtough.com/index.php?pag ... &Itemid=53

Brough a bit of stuff off them . No core return on the gears , another outfit is offering $415 plus $100 odd core charge . To help out the t/case you are looking for is a 410 with a 4wd light . At that price thou , just order some in . Maybe 4.62 diff gears if 5.12 is too much of a jump .

Chris

[wayfastwhitee]

http://www.trailtough.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=82&category_id=12&option=com_virtuemart&Itemid=53

Brough a bit of stuff off them . No core return on the gears , another outfit is offering $415 plus $100 odd core charge . To help out the t/case you are looking for is a 410 with a 4wd light . At that price thou , just order some in . Maybe 4.62 diff gears if 5.12 is too much of a jump .

Chris

yeah i thought i was sorted with my 5.12 diffs; might talk to one of my dad's mates and see if he'll take me for a quick spin in his (has 31s with 5.12s) -i'm still interested to see what its on road manner is like before i completely go away from using them.
thats a good price, my case was rebuilt about two years ago; but if i went the route of new gears i'd still like to get a kit with new bearings and seals etc.
I'm thinking flip a coin haha

[wayfastwhitee]

Standard suzuki tyres were 26.3 inch (from what i've found, could be wrong)
anyways...
The difference between 26.3 and 31 =17.87%
The difference between standard diff (3.73) and 5.12 = 37.3%
Really wish i had done the maths prior to purchase

[Madaz]

Some Flatdeck 413s came with a 3.1 low range

[wayfastwhitee]

Some Flatdeck 413s came with a 3.1 low range

http://www.trademe.co.nz/motors/car-parts-accessories/suzuki/auction-442391712.htm

yep, you mean just like that, or different?

i was looking at that, but for about 300 dollars more i could get this:
http://www.lowrangeoffroad.com/index.php/suzuki/samurai/transfer-case/suzuki-samurai-5-14-1-calmini-transfer-case-gearset.html

still just tossing up all my options