Swap to GU Diffs...How to?

[Hamish71]

Out of idle curiousity....

My brother in law was showing me the other day the portal axle assemblies that Marks Adapators does for the GU/GQ Patrol, moaning about them not having any for the Land Rover.

So, I started thinking, and drawing....and I cant see why you couldnt just install a whole GU axle/diff assembly onto the Discovery. Im sure Ive read about GU diffs being used by folk here before, mainly to handle large Chev engines.

So, what WOULD be required to fit GU diffs/axles onto a Discovery 2? Please dont ask WHY?...its Friday, I'm four beers down....so the answer is just "because".

[isuzurover]

It has been done plenty of times - have a search on outerlimits4x4 and possibly pirate as well.

Maggot on here has a rangie with nissota axles.

HOWEVER - the nissan has a centres rear, which is likely to cause vibration issues.

The toyota 80 series has an offset rear - so many people fit a nissan front and toyota 80 series rear.

Bush65 has a hybrid toyota/nissan front axle (using the best bits of both)\ - built by one of the guys on outerlimits.

There are also some goys on OL (e.g. bubs4x4) who could offset diff on a nissan rear for you - however the custom axle(half)shafts would be $$$.

[TonyC]

Out of idle curiousity....

My brother in law was showing me the other day the portal axle assemblies that Marks Adapators does for the GU/GQ Patrol, moaning about them not having any for the Land Rover.

So, I started thinking, and drawing....and I cant see why you couldnt just install a whole GU axle/diff assembly onto the Discovery. Im sure Ive read about GU diffs being used by folk here before, mainly to handle large Chev engines.

So, what WOULD be required to fit GU diffs/axles onto a Discovery 2? Please dont ask WHY?...its Friday, I'm four beers down....so the answer is just "because".

A Patrol rear is centred so you get odd tail shaft angles and vibes.
You must keep the ABS so you'll need to make that work.
I would have thought that Patrol axles plus the portals would be very wide on a Disco.
There are portals made for LRs, but not D2s AFAIK, dig up the tread by oilworker.

Sorry that's more a why not than a how to.

Tony

[Vern]

GQ is nearly a bolt in fit, Gu is much wider i think

[c.h.i.e.f]

which is a stronger overall drive line patrol or cruiser?

[robbotd5]

G'Day all.
I'm no expert in this field, but are the diff's in the D2 realy that weak compared to the Patrol diffs? I don't know. Just puttin it out there.
Regards
Robbo

[isuzurover]

which is a stronger overall drive line patrol or cruiser?

Depends - are you talking GQ, GU, 80s, 105s???

The Nissan H260 rear is the strongest rear by far. A slightly larger ring gear than the sals, and 1.5" 37-spline axles.

The 80s has the largest/strongest CVs, and Longfield varsions are available. Nissans have the smallest front axles. As mentioned, Bush65 built a hybrid nissota front, so he had the stongest bits from each.

But - whichever you fit, they will be miles stronger than rover axles, and will likely more than do the job.

G'Day all.
I'm no expert in this field, but are the diff's in the D2 realy that weak compared to the Patrol diffs? I don't know. Just puttin it out there.
Regards
Robbo

Yes. The rover diff has an 8.25" crownwheel, the nissan 260mm (10.25") and hypoid (stronger). The rover has 1.24" 24-spline axles, the nissan H260 1.5" 37-spline.

And to give you an idea of the difference the hypoid part makes, a toyota hilux rear crownwheel is only 200mm (8") but is significantly stronget than a rover.

[rick130]

GQ is nearly a bolt in fit, Gu is much wider i think

Only the axle tubes, the radius arms are in the same position. (i think, you would've thought I'd measure them up seeing as the GU has lived here longer than the 'fender)

[rick130]

A Patrol rear is centred so you get odd tail shaft angles and vibes.
[snip]
Tony

Pretty sure Hardy Spicer have a heavy duty double cardan joint just for this conversion these days.

[rick130]

G'Day all.
I'm no expert in this field, but are the diff's in the D2 realy that weak compared to the Patrol diffs? I don't know. Just puttin it out there.
Regards
Robbo

and to expand slightly on Ben's reply, the reason a Hypoid diff is stronger than the straight spiral bevel Rover diff (where the pinion is mounted on the centreline of the crown wheel) is that as the pinion is offset from the crown wheel centre line you automatically gain more tooth engagement between the two gears, reducing the loads on the teeth.

The downside is that it the further the pinion is offset it becomes more inefficient at power transfer and therefore generates more heat, like anything in life it's all a compromise.
The sliding/wiping action between the teeth on a hypoid diff is also a much tougher action on the gear oil which is why the sulphur extreme pressure additives were developed many years ago for diff oils.