what am i doing wrong? KZN130 front diff

[mfrsr]

trying to find the ratio of a Surf front diff, non LSD, without taking it out of the truck (don't have room in the shed at the moment).

I've measured the rear (btw, i'm counting number of turns of the driveshaft vs. one turn of the wheel) and come up with 4.1, which lines up with the body tag. but i know the history of this truck - used to belong to my brother, and he's put the wrong ratio diff in the front.

So i've counted the turns on the front driveshaft and come up with 2.7


Either that's one ****ing tall diff ratio or i'm missing something here. Anyone know what it is?

Cheers

[tallsam66]

Need more info
What year?
What model?
Petrol or Diesel?
Engine Capacity?
Auto or Manual?
What are the numbers from the VIN plate ?

[rokhound]

None of the above info is going to help you if the diff head has been replaced with something else.

When you were counting front, you made sure both free wheeling hubs were locked and only one wheel was turning?

[mfrsr]

Need more info
What year?
What model?
Petrol or Diesel?
Engine Capacity?
Auto or Manual?
What are the numbers from the VIN plate ?

No offense, but i've already given you that info...



It's a 130 series, so mid 90's.
model = KZN130...

KZ = 1-KZTE
1KZTE = Diesel

It's auto.


And the numbers off the tag won't help as the diff that's in the front doesnt match the truck.

All i'm trying to find out is why my count for the rear was 4.1 turns yet the front was 2.7 turns. Checked it on both front wheels too.

[mfrsr]

Yep, rokhound. Well, it hasn't got free wheeling hubs, just the factory 4wd select button on the t/case lever and solid hubs

Had to jack all 4 off the ground and and block one front wheel. Front driveshaft wouldn't turn otherwise, even with trans in N and t/case in N.

[skid]

so its the wrong ratio

do you plan on using it in 4wd dude

coz if you do then you are gonna have to take it out anyway, so you may as well take it out and then start counting teeth once its on the bench

is the rear factory, coz you may as well start looking for a replacement that is the same

[UBZ]

Sounds like the front diff ADD system is not engaged.
Front diff in the 130 has a disconect system for the passenger side axle.
With front jacked off the ground , 4wd engaged ,4wd light on on dash, transfer case in neutral , both front wheels should rotate when drive shalt is turned.
System can be manually engaged by removing the vacuum actuator on the front of the diff and sliding the locking collar over to engage pass axle.

If your confident the ratio is wrong personally I would pull the diff, as it quite a simple job.

[rangimotors]

Sounds like the front diff ADD system is not engaged.
Front diff in the 130 has a disconect system for the passenger side axle.
With front jacked off the ground , 4wd engaged ,4wd light on on dash, transfer case in neutral , both front wheels should rotate when drive shalt is turned.
System can be manually engaged by removing the vacuum actuator on the front of the diff and sliding the locking collar over to engage pass axle.

If your confident the ratio is wrong personally I would pull the diff, as it quite a simple job.

especially if you jam something like a socked/small block between the bump stop so you don't have to stuff around with the torsion bars.

[mfrsr]

I know it's a simple job guys. I don't have the room in the shed to do this just yet. I can't work outside the shed as the boss will go spare. And i need the truck useable by the end of the month.




I know full well it's the wrong ratio in the front. I fitted the bloody thing 3 years ago (brother supplied it, assured me it was the right ratio etc, etc)

If i can work out the ratio before i pull the truck to bits, if i'm really lucky it'll be a 4.5, then i can just swap the rear diff that's in there (the 4.1) for the 4.5 hilux diff head that's in my pile of bits.

But if that isn't the case, then i'll have to buy a new one, but even so, i still can't pull it apart and have it sitting there, it needs to be done and out of the main bay of the shed ASAP. It's not my shed.






Now, all im wanting to know is:





Why, when i tried to count the diff ratio in the front of an IFS Surf with an ADD, did i come up with a ratio of 2.7? And not something even vaguely close to 4.1/4.3/4.5?








Note, it's working fine in 4wd, it's engaged on the slider, light on on the dash. you can hear the vac solenoid click across. And it winds up horribly when you try and drive in 4wd across dry loose gravel.

UBZ: with 4wd button engaged, light up on dash and transfer case in neutral, front driveshaft can't be turned until the rear wheels are jacked off the ground. spin one front wheel and the other will turn the opposite way, says to me that the driveshaft's not able to turn.

my understanding of t/cases is that the neutral position of the lever disconnects the drive between the gearbox and transfer case, rather than between the front and rear driveshafts...?

[You Get That]

Easy.
jack one wheel off the ground mark your diff flange and spin the tire two times (not once)to see how many times the flange gos around.

[Heath]

Jack up the rear (both wheels off the ground) jack up one front wheel, engine running, put it in neutral (tcase) select 4wd button (engage the add system). Handbrake off too.

Now try to count the rotations of the front shaft for 1 wheel rotation.

Bit of a bugger of a job.

Back wheels need to be off the ground to let the front shaft turn when you spin the front wheel (transfer case locks these two together). If you can lock the front without engaging 4wd then skip this bit. Might be able to do this in Hi 4wd - but I dont know.

gearbox in neutral is for safety and to dissengage any drive to make things easier.

Engine running so vacuum system is operational.

one front wheel lifted only so that wheel can be spun and the grounded wheel forces the diff to rotate the drive shaft (not the other wheel).

Make sure everything is stable and well supported.

[mfrsr]

on that thought, would having the engine off make the ADD system revert back to unlocked/2wd? Like if there was a vaccum leak? is the actuator sprung to any position?

[Heath]

on that thought, would having the engine off make the ADD system revert back to unlocked/2wd? Like if there was a vaccum leak? is the actuator sprung to any position?

Not sure. Arent there two actuators? one for locking and one for unlocking?

Might be able to lock it and then switch off the engine. Not sure how the system works to be honest.

[mfrsr]

ok, so i was doing it wrong - cheers Weemsy...


I ended up pulling the front cover off the diff in place, counted the teeth and came up with 4.55, i already had a pair of 4.5's in the shed from my other suzuki so i've put one in the rear instead.

Glad that worked out, don't really have the $$$ to buy another diff.

[You Get That]

ok, so i was doing it wrong - cheers Weemsy...


I ended up pulling the front cover off the diff in place, counted the teeth and came up with 4.55, i already had a pair of 4.5's in the shed from my other suzuki so i've put one in the rear instead.

Glad that worked out, don't really have the $$$ to buy another diff.

?????
You said it was a KZN130 (1KZ surf) front diff and you say you got the diff gears form your other suzuki?

[mfrsr]

yeah, was a project that never got finished. SJ410 Flatdeck, hilux axles on a 3 link(prado radius arms) in the front and safari rear leafs. Motor was (first off) a EJ22, then a 2L-T, then a Mazda 2 litre then a CA18DE. Sold most of it on tardme. It started out as just longer shackles to clear a set of tyres, went to a coil spring front end, and from there it went off the rails...

Lucky i kept the diffs as spares for my 'cruiser...





edit: actually, bloody similar to what you've built

i just got talking to the right people(/person) at the wrong time, got kinda sidetracked on it. Once you lose interest in a project, you're pretty much screwed if you can't get back on track.



cheers to skid for taking the photo too, the only trip the poor thing ever made it to.