[gregdixon]

I went to swap my 4.3 gears with 4.8's but found the rear 4.8 crown wheel has a larger ID than the 4.3. I was told that the car I got the gears out of was an 01 GV. I will double check this with suzi store on Tuesday. I will see if they can show me the center they removed.

I am kicking myself for not checking the ID before starting. The bolt holes line up and everything looked normal. I have the front all assembled and ready to go.

I measured the ID's of the two crown wheels below and got the following:
4.3 108mm
4.8 118mm

What is the outside diameter of a vit center? my GV is 108mm.
Pics for reference

4.3 fitted




4.8 fitted

[gregdixon]

I have just read that the RD 79 air locker has an ID of 118mm. This would tell me If I get a 12 bolt rear vit centre I should be able to do the swap? Am I correct in thinking this?

[gregdixon]

I got the other center from Suzistore this morning ( Cheers brian ).

So what I have found out is that an auto GV has the same rear center as a vit but a manual GV has it's own center for the 4.3 gears.

If anyone is doing a ratio swap (4.8/5.12) on a manual GV make sure you grab the rear center as well as the gear set.

The front is no issue they will swap over easily.

[fordem]

What's the internal diameter of the manual GV rear - 108 or 118?

And whilst I'm about it - are we talking about 2.5 (H25) or 2.0 (J20) engined GVs?

[gregdixon]

Some one else replied yay

The 4.3 ratio crown wheel has and ID of 108mm. All other ratios are 118mm vit and GV.

They just had to do something different didn't they

The SQ625's (H25A engine) manuals are the only models to run the 4.3 ratio.

I believe the manual 2L have 4.8 diff ratios and the auto 2L has 5.12's.

[shabz]

gregdixon wrote:

If anyone is doing a ratio swap (4.8/5.12) on a manual GV make sure you grab the rear center as well as the gear set.

The front is no issue they will swap over easily.

I've picked up 4.625 ratio R&P's from an earlier vit - no centres.

Haven't gotten round to doing the swap yet (into my manual GV) - do you think i'll get the same issue in the rear?

[gregdixon]

shabz wrote:

gregdixon wrote:

If anyone is doing a ratio swap (4.8/5.12) on a manual GV make sure you grab the rear center as well as the gear set.

The front is no issue they will swap over easily.

I've picked up 4.625 ratio R&P's from an earlier vit - no centres.

Haven't gotten round to doing the swap yet (into my manual GV) - do you think i'll get the same issue in the rear?

I would say yes.
Measure the inside diameter of the rear 4.6 crown wheel to be certain. If its 118mm then they won't fit the 4.3 center.

[shabz]

I just measured the internal diameter of the rear 4.6 crown wheel i have. It's 118mm.

In the picks above it looks like the 4.8s will still bolt upto the 4.3 centre, even with the larger ID. Is that right or am i missing something?

I don't plan on fitting a locker, and given i have the matching pinion gear, it should still work right? (given that it bolts to the 4.3 center)

[gregdixon]

It will bolt on but I wouldn't run it with only the bolts supporting it. It need's to be snug over the center to keep it in place and centered.

I did have a very quick think about getting a spacer made up then you would also need a diff can to hold the cross shafts in or tack,punch them in place.

Just easier to get another center.

[shabz]

With changing the centre - will the standard axels fit the same? or will they need to be changed too? (ie same axel size/spline count?)


EDIT
Also why would suzuki make a slightly larger centre just for the 4.3s?

And even if the 4.6/4.8s don't fit snug on the 4.3 centre - why should this make any difference? I mean, with the snug fit and without bolts, the crown wheel will still spin freely wouldn't it? just the same and the non snug fit...It's the bolts that secure the crown wheel to the centre, not the snug fit so i don't understand how this would have any impact

i've never worked on diffs before and yet to pull mine out so sorry for the silly questions

[gregdixon]

shabz wrote:

EDIT
Also why would suzuki make a slightly smaller centre just for the 4.3s?

I wish I knew !!!!

Axles are the same spline count and diameter, the carrier/thirdmember is the same also.

IMO the bolts won't center the CW as there is play in them. Not alot but some, which may reult in them coming loose and playing havoc with all the turny bits in the diff.

[shabz]

gregdixon wrote:

shabz wrote:

EDIT
Also why would suzuki make a slightly smaller centre just for the 4.3s?

I wish I knew !!!!

Axles are the same spline count and diameter, the carrier/thirdmember is the same also.

IMO the bolts won't center the CW as there is play in them. Not alot but some, which may reult in them coming loose and playing havoc with all the turny bits in the diff.

Yes smaller...thats what i meant!

I thought that might be the case...but figured that with 12 bolts it shouldn't have any play. Ah well.....time to source a new centre i guess!

Can i ask how much suzi store charged the center? (im assuming it came complete with the side gears, bearings etc etc...)

[gregdixon]

I was in the same boat as you, just got the gear set only. I did pay $880 for them though.

Luckily Brian was kind enough to swap the center with my old one when I saw him on Tuesday.

[gregdixon]

gregdixon wrote:

shabz wrote:

EDIT
Also why would suzuki make a slightly smaller centre just for the 4.3s?

I wish I knew !!!!

Axles are the same spline count and diameter, the carrier/thirdmember is the same also.
IMO the bolts won't center the CW as there is play in them. Not alot but some, which may reult in them coming loose and playing havoc with all the turny bits in the diff.

My bad
Just letting everyone know that the rear third members are different between1999 auto and manual GV's. The gap between the pinon bearings is larger on the auto.
Suzistore to the rescue again .

I will start a thread in what I have found by doing this gear swap for future reference.