Gu diffs into GQ ....compatibility

[grunta11]

Hi,
How compatible are the GU wagon diffs front and rear, to bolt into GQ LWB? I'm weighing up the effort going ahead with a conversion rather than just swap centres.
I'm looking at a ratio swap from 3.9 to 4.1 after fitting 33,s and have come across a disc to disc front and rear out of a GU 4.5 petrol at a what I think is a good price. (Are all GU diffs & centres the same regardless of eng size, type) ?
What else do I need to prepare in readiness for this?
OR
is it really a bit overrated and should just make life easier for myself and do centres only....cheers!

[BigRAWesty]

They are a solid upgrade.
Wider track, bigger cv and bigger brakes.
It's best to grab the bigger brake master too.
You'll need..
Gu tie rod and drag link..
If your keeping the gq steering box you'll need a gq rod end to slip into the drag like at the steering box end.
Apart from that springs, shocks, radius arms all bolt straight up..
There is only one model diff that was different.
Cant remember it though. But gu 4.5 diffs should be good to roll.
I'm currently rebuilding my 2.8 gu diffs with 4.6 centers to go in the gq

[threedogs]

@ Kallen I think it was a diff from a ute that was different
One you could shave a bit off

[grunta11]

They are a solid upgrade.
Wider track, bigger cv and bigger brakes.
It's best to grab the bigger brake master too.
You'll need..
Gu tie rod and drag link..
If your keeping the gq steering box you'll need a gq rod end to slip into the drag like at the steering box end.
Apart from that springs, shocks, radius arms all bolt straight up..
There is only one model diff that was different.
Cant remember it though. But gu 4.5 diffs should be good to roll.
I'm currently rebuilding my 2.8 gu diffs with 4.6 centers to go in the gq


Thanks for the info bigwesty 👍

[Sharky1]

I 2nd what bigwesty said but just double check that the ratios on the 4.5L are 4.11 & not 4.23 or 4.37. The compliance plate will tell you what they are unless they've been changed.

[grunta11]

just realised my error here, i already run 4.1 gears, therefore looking for at least 4.375 to bring back to standard.

BUT as the autos run a 30% overdrive of .694 (compared to 17% overdrive .836 for the manuals ) i was considering what 4.6 gears would do for the towing performance at highway speeds. The highway RPMs would be still lower than the manuals running 33`s with stock ratios........by the time i add my winch, steel bullbar scrub bar/steps, twin rear wheel carrier, roof rack, 80lt fridge, missus kids, gear, camper trailer..wheew!.........the ol girls gonna need a bit of a hand to push up the little hills yet alone headwinds and big hills...just a thought.....

[mudnut]

The pinion flange on my gq 4.3 was smaller than the gu so I also had to swap them over.