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GQ Conversion To GU Front End

Posted: Sun Sep 02, 2007 11:38 am
by smee2u
Hi, I am converting my GQ front end over to a GU front axles, CV's, rotors, calipers etc.
I have already sorted out the steering box to a GU unit, but am not sure if l will need to throw on a GU brake booster to handle the larger twin pot calipers. Can anyone provide info on this ?

Posted: Sun Sep 02, 2007 1:39 pm
by tna racing
i allways though gu axels were 30mm longer so it couldnt be done ?

p.s see u live in tralgon im from yallourn north

Posted: Sun Sep 02, 2007 1:52 pm
by steveoo
i am also in the same process..

smee2u:- How much did you pay for your steering box??? also where from

Posted: Sun Sep 02, 2007 4:09 pm
by smee2u
i allways though gu axels were 30mm longer so it couldnt be done ?

p.s see u live in tralgon im from yallourn north

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After chatting with cheezy racing, apparently l can utilise my GQ diff centres which l have alredy rebuilt and air lockered (only just decided to go GU units after everything was already done), Apparently l can cut a smaal section of spline off the axles and they will fit the GQ centre. As for being longer, yes they are (about 40mm, l think-havent measured) but l dont think that will cause any engineering dramas. Just run wider flares

Posted: Sun Sep 02, 2007 4:22 pm
by smee2u
am also in the same process..

smee2u:- How much did you pay for your steering box??? also where from[color=orange][/color]


boxes ranged from between $500 to $880 when l was looking.
Got quoted the upper margin from a wreckers. Got mine for $600 locally through friend of a friend. Did see one for sale in the "for sale - driveline. bits and pieces section" back in the index page l think.

Posted: Sun Sep 02, 2007 7:00 pm
by turbo gu
Why don't you just bolt the whole diff in? A whole lot easier!! just swap your centre over if it has a locker. I just a gu box for $410 delivered

Posted: Sun Sep 02, 2007 7:53 pm
by steveoo
thats what i am doing putting in a complete GU front and rear diff in i have bent my front one so i might as well do it once and do it propley

Posted: Mon Sep 03, 2007 2:12 pm
by smee2u
Steevoo, you ought to look into getting the front axle housing laminated if your hitting stuff hard enough to bend the front axles

Posted: Mon Sep 03, 2007 4:42 pm
by steveoo
It was from the old owner that the front axle got bent. only noticed it when we put the bigger tyres on

Posted: Mon Sep 03, 2007 5:41 pm
by Draven
Has anyone had issues with the steering with a wider front diff... Im just about to do mine as well :)

Posted: Mon Sep 03, 2007 8:00 pm
by hammey
Draven wrote:Has anyone had issues with the steering with a wider front diff... Im just about to do mine as well :)
as long as your bump stops hit which mine did easily, all good....

Posted: Mon Sep 03, 2007 8:16 pm
by Mick.
steveoo wrote:thats what i am doing putting in a complete GU front and rear diff in i have bent my front one so i might as well do it once and do it propley
When doing the rear GU diff conversion there is a little hitch that needs sorting out.

The end of a GQ tail shaft wont bolt up to a GU diff but there are 2 ways of sorting this problem out. What I did was us the rear half of a GU tail shaft and slip that into the front of my GQ tail shaft.

The other way would be to change your pinion but I would imagine that being a bigger job.

The front tail shafts bolt straight in though. :lol:

Cheers Mick.

Posted: Mon Sep 03, 2007 8:32 pm
by turbo gu
Mick. wrote:
steveoo wrote:thats what i am doing putting in a complete GU front and rear diff in i have bent my front one so i might as well do it once and do it propley
When doing the rear GU diff conversion there is a little hitch that needs sorting out.

The end of a GQ tail shaft wont bolt up to a GU diff but there are 2 ways of sorting this problem out. What I did was us the rear half of a GU tail shaft and slip that into the front of my GQ tail shaft.

The other way would be to change your pinion but I would imagine that being a bigger job.

The front tail shafts bolt straight in though. :lol:

Cheers Mick.
I did one just recently and it bolted straight up. If they are out of a 2.8l Gu it might have a smaller Pinion flange than the other motors

Posted: Mon Sep 03, 2007 8:41 pm
by Mick.
turbo gu wrote:
Mick. wrote:
steveoo wrote:thats what i am doing putting in a complete GU front and rear diff in i have bent my front one so i might as well do it once and do it propley
When doing the rear GU diff conversion there is a little hitch that needs sorting out.

The end of a GQ tail shaft wont bolt up to a GU diff but there are 2 ways of sorting this problem out. What I did was us the rear half of a GU tail shaft and slip that into the front of my GQ tail shaft.

The other way would be to change your pinion but I would imagine that being a bigger job.

The front tail shafts bolt straight in though. :lol:

Cheers Mick.
I did one just recently and it bolted straight up. If they are out of a 2.8l Gu it might have a smaller Pinion flange than the other motors
It was. I did the conversion for the 4.6 ratios.

Cheers Mick.

Posted: Mon Sep 03, 2007 9:47 pm
by bru21
i spapped the pinion flange on mine too easy. the brakes i left alone ie gq booster etc. nissan brakes are about a good as cheese against a hot plate.

Posted: Tue Sep 04, 2007 7:03 am
by Draven
hammey wrote:
Draven wrote:Has anyone had issues with the steering with a wider front diff... Im just about to do mine as well :)
as long as your bump stops hit which mine did easily, all good....
awesome, how about the 'tracking' of the vehicle ? ive heard the wider front diff can make it a bit skitish.

Posted: Tue Sep 04, 2007 7:40 am
by hammey
Draven wrote:
hammey wrote:
Draven wrote:Has anyone had issues with the steering with a wider front diff... Im just about to do mine as well :)
as long as your bump stops hit which mine did easily, all good....
awesome, how about the 'tracking' of the vehicle ? ive heard the wider front diff can make it a bit skitish.
5 close mates all have GU front ends, I think coll of here is the only one with a GU rear.

Cant say i've even ''heard'' of tracking problems.Not to say they cant happen. I stayed with the GQ rearend for the tighter turning circle or is it lack of funds ;)

cheers smitty

Posted: Tue Sep 04, 2007 8:02 am
by dirtyGQ
15mm wheel spacers on both sides of the gq rear diff if a gu front is fitted .

Posted: Tue Sep 04, 2007 10:24 am
by bj on roids
i just left it narrower, pulls through trees and follows easier, plus cheaper and less work :lol:

Posted: Tue Sep 04, 2007 10:27 am
by nastytroll
GU cab chassis with leaf rear has a narrow rear diff, not sure by how much but alot norrower then the front

Posted: Tue Sep 04, 2007 10:40 am
by Sandy Rut
My 88gq booster handles the GU twin pots no worries.

Posted: Thu Sep 06, 2007 4:59 pm
by steveoo
So lets get a list going

GU front


GU rear
Possable problem with tail shaft


Brake parts
some people say master cylnder no problems others say upgrade
Master cylinder the gq has a 27mm bore in it and the gu one has a 25mm bore on the inside of it. so from what we can work out the GQ one is better than the GU one.

GU sterring box
they recommend to upgrade to a GU pump but if you dont you can run a GQ one and run a transmition line cooler

Posted: Thu Sep 06, 2007 5:45 pm
by smee2u
I got differing info on the master cylinder. Some said dont bother, another trusted source said a 94 onwards efi GQ has stonger brake booster than my 89 GQ deisel . Either way, the GU brake booster wont just bolt on without serious mods.
I got my GU rear diff assembly at the same time l picked up the front, and l can see no discernable difference between the two pinions. My front and rear GU diffs are off a coil sprung ute by the way.
I will be putting the rear GU diff on.
For the kind of work lm doing, the GU steering box is highly reccomended for its additional strength in the pitman arm, as l have heard of quite a few ppl on the race scene breaking the GQ steering boxes undre heavy going.

Posted: Thu Sep 06, 2007 6:58 pm
by Mick.
smee2u wrote:I got differing info on the master cylinder. Some said dont bother, another trusted source said a 94 onwards efi GQ has stonger brake booster than my 89 GQ deisel . Either way, the GU brake booster wont just bolt on without serious mods.
I got my GU rear diff assembly at the same time l picked up the front, and l can see no discernable difference between the two pinions. My front and rear GU diffs are off a coil sprung ute by the way.
I will be putting the rear GU diff on.
For the kind of work lm doing, the GU steering box is highly reccomended for its additional strength in the pitman arm, as l have heard of quite a few ppl on the race scene breaking the GQ steering boxes undre heavy going.
The pinion difference is very small and not noticable until you try and bolt it up.

Cheers Mick.

Posted: Fri Sep 07, 2007 8:37 am
by smee2u
I will be transferring my freshly rebuilt 4.6 GQ diff centres over to the GU housing anyway.
Will be doing this front and rear.
Is it only the pinion on the 2.8 GU patrol that is a differnt size ?

Posted: Fri Sep 07, 2007 9:26 pm
by steveoo
so has anyone else done this

Posted: Sat Sep 08, 2007 4:26 pm
by Xtreme4x4
steveoo wrote:so has anyone else done this
I swapped my 92 SWB front for a 99 GU and the only problem was the length fo the Panhard rod and the steering rod which I would guess the GU rods would be the correct length.My shorty is LHD so I could not find LHD GU rods.
The rear was still drum brakes so I swapped it for a later model GQ rear with discs,it bolted right in with no problems.
I didn't change any other brake components (booster and master cylinder)and my brakes work like a charm.With regards to the different track widths I don't have any problems with handeling at all.

Dennis

Posted: Sun Sep 09, 2007 2:08 pm
by BENNNO
As far as rear tail sharfts go the bolt pattern is just different i think. i had similar prob with my mq, putting gq diff under, i had a diff out of a 4.2 wich was something like 75mm to 75mm pattern and the flange of my trans was the same as a 3ltr something like 65mm to 65mm.... so just had to get two tail sharfts and pull the spline out of the 4.2 and slide it up the coit of the 3ltr!! would probably have simillar problem with going gq to gu!! bit more money but cheaper then getting one custom made!!

hope this helps...Happy Building,
Benno

Posted: Sun Sep 09, 2007 6:20 pm
by rvh96
smee2u wrote:I will be transferring my freshly rebuilt 4.6 GQ diff centres over to the GU housing anyway.
Will be doing this front and rear.
Is it only the pinion on the 2.8 GU patrol that is a differnt size ?
in GU yes only 2.8l has the small flange in GQ rb30s and 2.8 deisel had the small flange

Posted: Sun Sep 09, 2007 7:16 pm
by turbo gu
Xtreme4x4 wrote:
steveoo wrote:so has anyone else done this
I swapped my 92 SWB front for a 99 GU and the only problem was the length fo the Panhard rod and the steering rod which I would guess the GU rods would be the correct length.My shorty is LHD so I could not find LHD GU rods.
The rear was still drum brakes so I swapped it for a later model GQ rear with discs,it bolted right in with no problems.
I didn't change any other brake components (booster and master cylinder)and my brakes work like a charm.With regards to the different track widths I don't have any problems with handeling at all.

Dennis
The panhard should be be right lenght to bolt straight up as the width difference is at the swivel hub area. panhards are the same lenght GQ/GU