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Are Vit 3spd auto transfer cases rare?

Posted: Sun Jan 23, 2005 11:21 pm
by SiKiD_01
just wondering if anyone knows if these existed in australia.

i haven't heard much about the 3 Door vitara with a 3 speed auto. i'm interested in the 3 door model only, not 5 door models. apparently these have good ratios for running up to 33"-35" tall tyres. i think this may be better than forking out for rock hoppers. up here, i dont have too many hills or big rocks, just a lot of dirt and mud. so i dont need super ultra low gearing.

and if these do exist, what are the chances that the 3spd auto transfer will bolt on to the 5spd manual box?

thanks for any help.
Steve (in search of lower gearing)

Re: Are Vit 3spd auto transfer cases rare?

Posted: Sun Jan 23, 2005 11:43 pm
by christover1
I don't have all your answers, but I know we do get the 3 speed auto in oz.
Only on the very early carby model Vitaras.
I imagine the early and later vits have same bolt patterns, but don't know fer sure.
the 3 speed is a trimatic like in many other cars, corrollas and early holdens especially. they have a good reliability reputation,
christover

Posted: Mon Jan 24, 2005 7:43 am
by OldGold
If the vit 3 spd auto has a reputation for reliability then it shares absolutely nothing in common with a holden trimatic ;)

Posted: Mon Jan 24, 2005 7:54 am
by cj
No difference in the t-case ratios, don't know where you got from. The Tri-matic auto isn't that great, the Aisin-Warner 4spd is much better. The plus for the 3spd is that it is not computer controlled so is an easier swap.

Posted: Mon Jan 24, 2005 8:10 am
by cj
8v 1.6 3spd auto
1st 2.400:1
2nd 1.479:1
3rd 1.000:1
High 1.000:1
Low 1.816:1
Diff 4.625:1

Crawl ratio 1st low 20:1

5spd manual 3.652:1, 1.816:1, 5.125:1 Crawl ratio 33:1

3spd auto with manual Diff ratios: Crawl ratio 23:1

Your crawl ratio will drop from 33:1 to 23:1 certainly not rockhopper league and your engine braking will go out the window with the auto.

Posted: Mon Jan 24, 2005 9:16 am
by Dozoor
cj wrote:8v 1.6 3spd auto
1st 4.400:1
2nd 1.479:1
3rd 1.000:1
High 1.000:1
Low 1.816:1
Diff 4.625:1

Crawl ratio 1st low 37:1

5spd manual 3.652:1, 1.816:1, 5.125:1 Crawl ratio 33:1

3spd auto with manual Diff ratios: Crawl ratio 41:1

Yes, your crawl ratio will jump from 33:1 to 41:1 certainly not rockhopper league but your engine braking will go out the window with the auto although I don't think you're doing too many big steep descents.


Where did you get the figure for first gear Cj ,
If this is the right figure then auto boxs for crawlers are about to take a leap foward, currently the lowest first gear avialable in a viable production auto is 3.1 , TH700 . As far as i am aware TH180 boxs = garden variety tri,s are around the 2.5-1 for first , as far as the asian warner box goes the performance world must be a step behind ,

The torque converter provides around 1.5-1 somtimes up to 2-1 , but assuming the proir converter ,Then times first gear- transfer and 5.1 diffs.
Would give a usable ratio of 61.4-1 .

But reality is more like the the 2.5 for first - if they did run the other gear set with a 4.4 first and a 1.4 second , the early vits would be just about undrivable , The combination of a lack of torque and a miss matched gear set like that , the vehicle would faulter on the upchange from first to second severely eg: the 4.4-1@3500RPM = 795 Rpm at the tail shaft when the box changes to second 1.4-1@1113RPM=795 at the tail shaft
1100 Rpm isn,t much above idle = a pig of a gear set , for an auto .
engine screeming in first down to idle at the change errrr :? Don,t think a factory would do it on a three speed auto,

JMO,

Oh bye the way, Trimatics Rock if built right they can handle 300hp up :)

Posted: Mon Jan 24, 2005 10:22 am
by cj
No, my mistake should've been 2.4. Manuals generally seem to have better crawl ratios than autos but the autos torque converter helps. I've corrected the calculations.

Posted: Mon Jan 24, 2005 4:14 pm
by Dozoor
No worrys Cj , :) Damn shame they havn,t got it though :cry: would be exellent, :lol: