GQ Diff Compatibility

A commonly asked question is “Can I use GQ diffs in my MQ?”. The simple answer is NO, they will not bolt in. Like anything though, they could be fitted with substantial fabrication and associated work, much like you could fit a jet engine in the boot if you wanted.

The intent of this page is to describe the mixing and matching of parts between MQ and GQ diffs, not how to fit the diffs into a MQ. This will be covered by the (non-specific) Diff Conversions wiki page.

FYI, H233 diff was used in most MQ and probably even MK models. It is not known for certain if H233B were available in MK Patrols, but there are reports they were. It may be that the very last models of MK used the H233B, in preperation for the release of the GQ / Y60. If you need to indentify your diff, refer to the table on Diff Info wiki page.

Front Diff (H233B - 31 Spline)

The front diff in MQ’s is the C200 model and the GQ uses a H233B model.

Third Member

Compatibility: Varies

The GQ front diff is a banjo type with removable third member. As such, the ring, pinion, and diff centres are not compatible with the C200 salisbury type diffs.

Some parts are compatible with the H233/H223B rear diff of MQ patrols though, as discussed below. In addition, the third member will bolt into a MK H233B with no modifications. It will not bolt into a H233 due to the different bolt pattern and depth (pinion ~4cm longer).

No parts are compatible with the H260 rear.

Ring and Pinion

Compatibility: Depends…

Regardless of compatibility, the GQ R&P will be reverse cut to suit a front differential. It would not be recommended to use one within a rear diff.

The R&P will swap into a MK H233B rear third member. They will not bolt into a H233 diff, due to different bolt size and PCD to the centre, also the pinion are ~ 4cm longer.

Centres (LSD/Lockers)

Compatibility: Compatible

They are entirely compatible with a MK H233B rear diff. They are not directly compatible with a H233 diff, due to different bolt patterns to the ring.

Centres (Lokka/Mini-Spool)

Compatibility: Compatible

These lockers replace the spider gears within an open centre. They are entirely compatible with a MK H233B rear diff. They should be compatible with a H233 diff.

Axles

Compatibility: Not Compatible

A GQ diff is wider than an MQ diff, which means the axles are longer. They also have more splines to the centre. Hence, they are not compatible.

CV

Compatibility: Compatible

A standard GQ CV can be used in a C200 front diff, but the GQ free-wheel hub must also be used. Please refer to the [GQ CV Conversion][Wiki: gq cv] page.

Swivel Hubs

Compatibility: Compatible

GQ swivel hubs can be used on C200 diff knuckles, as the king-pins are the same size. According to this Outerlimits4x4 thread, there are some minor differences with steering geometry. Also, the brake caliper mounts are offset from the wheel slightly different.

On an MQ, the tie rod connection points are located mid-height and at the front of the swivel hub. On a GQ, they are located down low and behind the swivel hub. This is considered an undesirable trait of the GQ swivel hubs and some people actually change to the MQ system for better clearance (as discussed in the Outerlimits4x4 thread linked above). The tapered hole for the tie rod studs are the same size on MQ and GQ.

Brakes

Compatibility: Compatible

Refer to the GQ Brake Parts Compatibility page for info.

Rear Diff (H233B - 33 Spline)

MQ’s feature many different models of rear diff, being the C200, H233 and/or H233B in MK, and H260 models. H233 (+B) are the most common rear diff used in Australia, whereas European countries often have the C200. H260 is reserved for heavy duty applications.

The GQ also feature H260 in the rear of some heavy duty models, however they mostly have H233B rear differentials.

The following will compare the H233 (+B) found in the rear of MQ’s to the H233B found in the rear of GQ’s.

No parts from the rear of any GQ will be compatible with a rear C200.

Most parts from the rear of a H260 should be compatible (including lockers and LSD), the exception being axles due to different lengths.

Third Member

Compatibility: Not Compatible

The H2** series diffs are all banjo style, and the third member is the pinion, ring, and centre combined assembly that bolts into the axle housing. The complete third member assembly is not compatible, for a few reasons, including;

• The ring gear bolt size and PCD is different on a H233B compared to a H233. The ring would swap into a MK H233B though.
• Pinion flange bolted connection (to the drive shaft) are wider bolt centres on GQ.
• More splines for the diff centre on GQ rear H233B than any MQ H233 (+B).
• Diff centres (including all types of diff locks) as mentioned have more splines and different bolts. This means a GQ rear diff lock cannot be used in an MQ!

Axles

Compatibility: Not Compatible

A GQ diff is wider than an MQ diff, and the ‘pumpkin’ is located in the centre on GQ (offset to RH side on MQ). Further to this, the centre splines are larger on GQ.

Brakes

Compatibility: Not Compatible

GQ feature disc brakes on the rear, whereas MQ are only drum. Refer to the GQ Brake Parts Compatibility page for further info.

Bearings

Compatibility: Unknown

It is not know if the bearings and seals located at the wheel ends of the diff housing are the same.