Outer Limits 4x4 Board

EDITED:

Ive started the installation of a lockright into the rear diff of my 90' Sierra. I got the kit without couplers.

Anyway, so far ive just removed the rear diff, i'll do the rest tomorrow.
I Noticed the rear diff has "front" written on it with texta, so im guessing it was purchaced from a wreckers at some stage by a previous owner.

Is it possible that a front diff centre was fitted to the rear of my Sierra?
How can i tell wether it is or not?

Will this cause me any problems with a Lockright install?

From reading the directions, the 2 side gears are re-installed on opposite sides when fitting the locker, did i read it right, and why is this the case?

Thanks
Mike

EDIT: After looking at the centre, it only has 2 pinions. So it must be a front centre, but has the rear 26 spline side gears.
Can i still fit my Lockright?

Mike

This really sucks. Why would someone put a 2 pinion diff in the rear?

So is there any way it can be fitted?

I'm seriously spewing about this because ive wasted all this time removing the diff. Im thinking i should just weld the diff now and sell the locker!

Mike

What year is your zook mate? 88.5 and earlier WTs came with 4 pinion front diffs and so did 1.3 NTs i'm pretty sure. If yours is 2 pinion in the rear maybe your front diff is a 4 pinion. Pain in the butt but it might pay to check before you go buying a 4 pinion diff to fit the locker in.

THey install the side gears on opposite sides so you have a nice clean edge to run on when under load. THe 4 pinion diff is stronger so you should prob install it into a 4 pinion.

Well if you pulled out a 2 pinion diff from the rear and it was working before you pulled it out it must be possible!

I'd hold out and fit it into a 4 pinion diff.

The way the ring gear bolts to the hemisphere is completely different on a 2 pinion centre. It looks very different to the one in the pics in those install instructions. I have one at home. I'll try and get some pics up in the morning of what a 2 pinion looks like.

A 2 pinion has a single pinion shaft running across the middle. The 4 pinion has one pinion shaft running right through the middle, and 2 smaller shafts that meet inside the little cube in the middle. Does the carrier have 2 holes or 4 for the shafts to come in from?

Your truck had been modded so maybe someone had broken one and sourced a 2 pinion as a replacement?

Yeah, it only has one shaft running through the centre of it! damn it haha!

Im currently researching welded rear diffs at the moment cause i have the diff out now, so may as well.

I dont want to spend any more money either!

Mike

zookimal wrote:The way the ring gear bolts to the hemisphere is completely different on a 2 pinion centre.

the ring gear bolts up the same as a four pinion. to have a 2 pinion in the rear someone along the line has put the carrier from a late model vit into your diff, these have a 2 pinion 26 spline carrier.

joeblow wrote:

zookimal wrote:The way the ring gear bolts to the hemisphere is completely different on a 2 pinion centre.

the ring gear bolts up the same as a four pinion. to have a 2 pinion in the rear someone along the line has put the carrier from a late model vit into your diff, these have a 2 pinion 26 spline carrier.

Is there any advantage to doing this? (gearing or otherwise?)

Couldn't be just to save money, not that i've looked yet, but i can't imagine 2nd hand rear diffs cost that much....
Vitara diff probably cost more?? then you have to swap over ring and pinion?

Sorry, just really.... um... dumbfounded, and annoyed.

Mike

Ok, excuse my confused terminology Joe. I think you know what I mean though.

The way carrier itself bolts together?

yes... i get ya now. 2 pinion carrier held together by ring gear bolts....4 pinion has an end-cap with m8 bolts.

Im guessing Joe must be correct on his Vitara diff theory.

Crown wheen has 41 teeth and pinion has 11. So 3.7:1? Is that the correct gearing for my model sierra (90' SJ70)?

Because the locker wont fit this diff I ended up welding the side gears (following guide in bible). Only because i had the diff out and open, so i thought i'd give it a go. If I like it, it stays and Lockright is up for sale, if not i will source another diff which the locker will fit into.
I have only been around the block a few times, but so far so good.

Mike

Heres a pic of it, if anyone can confirm it to be Vitara or otherwise (Welding and grinding of side gears not complete in pics):

yep, 3.7 is right. and it does seem someone has put a 26 vit front in your rear.

put the lockright in your front diff

sheps wrote:put the lockright in your front diff

Then i'll have the same problem! Only 2 pinions in front too.
Plus i like being able to turn corners (apparently difficult with a front auto)

Mike

yes but isnt your rear diff a 2 pin vitara diff.
if you have a sierra diff it will fit.
the lockright without couplers fit both 2 and 4 pin 1.3 sierra diffs.
lots of people have lockrights in there front diff and like
them, i am on of them. i would have thought that someone that welds diffs
wouldn't be that concerned with driving comfort.
if you don't want the locker sell it cheap to
lump a charcoal.

sheps wrote:yes but isnt your rear diff a 2 pin vitara diff.
if you have a sierra diff it will fit.
the lockright without couplers fit both 2 and 4 pin 1.3 sierra diffs.
lots of people have lockrights in there front diff and like
them, i am on of them. i would have thought that someone that welds diffs
wouldn't be that concerned with driving comfort.
if you don't want the locker sell it cheap to
lump a charcoal.

sheps wrote:yes but isnt your rear diff a 2 pin vitara diff.
if you have a sierra diff it will fit.
the lockright without couplers fit both 2 and 4 pin 1.3 sierra diffs.
lots of people have lockrights in there front diff and like
them, i am on of them. i would have thought that someone that welds diffs
wouldn't be that concerned with driving comfort.
if you don't want the locker sell it cheap to
lump a charcoal.

I'm pretty sure they don't fit 2 pinion diffs??

I had one fitted to a 2 pinion front diff in the front of one of my old sierras. Was fitted by a specialist diff workshop, back in the days before I had either stripped a zook diff or knew there were both 2 and 4 pinion diff centres. They supplied and fitted it, never said anything, and I was none the wiser at the time.

It worked, but unlocked very easily, and regularly. I often thought it was broken. Possibly saved me some axles and cvs as it would unlock and release the load, but did put some shock through it as it constantly locked and unlocked. For better or worse I don't know. It did provide decent traction, and was a big help offroad (cornered easily as it wouldn't stay locked), but now that I have a few diffs around, I wouldn't use anything other than a 4 pinion centre.

How does it work with 2 pinions?
the lockrights come with 2 spacers which sit inside the locker gears (as shown in pic) With a 4 pinion diff you have the "connector piece" (piece which long pinion shaft and 2 short pinion shafts fit into) Which is flat and the spacer/washer sits on.
If you have a 2 pinion diff you dont have this piece, so the spacer can fall into the diff cant it?

Then the fact that the lockright gears have 4 slots cut into them, to sit onto the pinion shafts. If you only have 1 pinion shaft whats to stop the gear from flopping around inside?

I do believe that some people do fit them to 2 pinion diffs, i just cant understand how??

Mike

mike_nofx wrote:
I do believe that some people do fit them to 2 pinion diffs, i just cant understand how??

Mike

by following the instructions.
get on here and yak to ball, he fitted mine.
http://www.auszookers.com/index.php