Another Diff question

popup · Post by **popup** » Sun Dec 22, 2013 8:58 pm

Does anyone think the crownwheel and pinion would fit from this? I'm going to ask if the crownwheel and pinion can be separated to save on shipping.

http://www.ebay.com.au/itm/mitsubishi-t ... 3cd56d5c08

From what I've picked up is that if you have 4 stud/lug wheels you have a smaller diff (pre 85?) and if you have 5 stud/lug you have the larger diff.
4 Bolt and 6 Bolt axles shouldn't make a difference to diff size. I think this diff would be for the larger diff.

The Diff always needs be low pinion so that seems to be from earlier Mitsubishis years, like the 2nd gen Triton. And that seems to be the same as a MightyMax/D50 so it all seems to make sense. And it seems like the 4.222 Ratio is from the 2.6 Petrol. I think the 2.5 Diesel have 4.6xx Ratio.

Komeuppance · Post by **Komeuppance** » Mon Dec 23, 2013 1:24 am

To fit a 4.22 I think you need a big diff??

In the US 4 bolt axles are all the same diameter, but the bolt pattern on the flange is slightly smaller on the non LSD axles. A little drilling and they will bolt right up. Only 83 had the small diff here, and our 4 stud cars had the same diff as 5 stud (unless it was 6 bolt).

6 bolt axles are a larger diameter and will only work with the larger diameter parts. The hub itself is the same, just with a 6 bolt flange. The differential casing is different as well, and 10lbs heavier than the 4 bolt big diff.

-Robert

redzone · Post by **redzone** » Mon Dec 23, 2013 8:22 am

Robert, no drilling reqd, you just keep the drive flanges that match the half shafts. The internal spline size is IDENTICAL, I have no idea why they changed the 4 bolt flange pattern...

JDSTAZ45 · Post by **JDSTAZ45** » Mon Dec 23, 2013 9:10 am

The size change in the 4 bolt flange is to differentiate between 4 & 5 stud models.
My 5 stud GSR-V has the small 3.9 diff with the larger 4 bolt flanges.
But again, an easy fix is the keep the flanges that go with the drive shafts.
There is a model reference somewhere on the forum between the tritons & pajeros (equivalents) that work with the BIG diff housings.

Komeuppance · Post by **Komeuppance** » Mon Dec 23, 2013 11:13 am

Yeah, should match up the correct flanges, but the incorrect ones can easily be made to work if you don't have a match.

If you've got the diff apart... would be a good time to install an LSD setup lol.

-Robert

popup · Post by **popup** » Mon Dec 23, 2013 10:36 pm

I think I may take a gamble and hope its the right part. I know my diff uses the 4 Bolt driveshafts, and I'm pretty sure the diff is larger. The parts manual for Euro Starions lists one diff for <85 and a different part number for >85.

I think most Euro starions were fitted with LSD from factory.

ProZac · Post by **ProZac** » Tue Dec 24, 2013 7:41 am

Your's, being an 86 should definitely have the larger diff :-).

Keen to hear how you get on.

redzone · Post by **redzone** » Tue Dec 24, 2013 2:33 pm

JDSTAZ45 wrote:The size change in the 4 bolt flange is to differentiate between 4 & 5 stud models.
My 5 stud GSR-V has the small 3.9 diff with the larger 4 bolt flanges.
But again, an easy fix is the keep the flanges that go with the drive shafts.
There is a model reference somewhere on the forum between the tritons & pajeros (equivalents) that work with the BIG diff housings.

But why? There is no logical reason for this change. Manufacturers usually only do this as a warning that they have changed something else, changing the drive flange & corresponding bolt pattern on the half shaft doesn't actually make any sense at all!

A 1mm change doesn't exactly improve strength does it...

Muz · Post by **Muz** » Tue Dec 24, 2013 9:33 pm

I guess MMC may have brought them into production to align with the homologation of the bigger shafts with the 6 bolt flanges. They homologated these components as. Variant option extension number 22-15VO for group A as of January 1 1987. Just putting 2 and 2 together.

Komeuppance · Post by **Komeuppance** » Tue Dec 24, 2013 9:47 pm

redzone wrote:changing the drive flange & corresponding bolt pattern on the half shaft doesn't actually make any sense at all!

Mitsubishi made sense?! I must have missed it that day lol. They've always seemed stubborn and eccentric in their engineering decisions lol... I bet they did some stuff just because they could, and it was amusing to them. Must be what attracts me to Mitsubishi lol.

-Robert

JDSTAZ45 · Post by **JDSTAZ45** » Wed Dec 25, 2013 10:26 pm

redzone wrote:
JDSTAZ45 wrote:The size change in the 4 bolt flange is to differentiate between 4 & 5 stud models.
But why? There is no logical reason for this change. Manufacturers usually only do this as a warning that they have changed something else, changing the drive flange & corresponding bolt pattern on the half shaft doesn't actually make any sense at all!

A 1mm change doesn't exactly improve strength does it...

I forgot to add that there is also an increased thickness to the drive shafts...I don't think it's quite 1mm, but a thicker shaft nevertheless.
That would make a difference! But the spline is still the same.
I reckon Mitsu would have beefed up the suspension with introduction of the widey in mid-85 and as usual mix & match parts to suit them for their domestic market.
With the JD having a large diff (85-86/87), I presumed the 3x GSR-V's I've owned (86-87) were large diffs as well. But no, all small diffs!

Austarion

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