GQ TD42 to GU ZD30 xmas conversion

[Mike_1]

Hi all,
I just wanted to share with others my xmas time that I have spent with my flatmate doing conversion from 1990 GQ TD42 into 2000 GU ZD30. I will try to add a bit of history on why I have done it, but I'd like to mainly focus on difficulties that we had doing engine/gearbox/diffs swap as they might be helpful for someone that thinks about it.

Long story short:

Donor car:
- 1990 white Nissan Patrol DX TD42
- 4.11 diffs
- factory rear difflock
- ARB side steps/rails off GU (shortened approx. 5cm each to fit GQ)
- GU TD42 2003 engine with an aftermarket turbo
- 4" EFS Extreme suspension with ToughDog panrods and extended brake lines



Why:
- corrosion showed up in the drivers and passenger's floor
- most of the panels were scratched/corroded
- my partner wanted an upgrade :)

Target car:
- 2000 blue ST GU with blown ZD30 motor
- 3.9 diffs as previous owner bought himself a DX GU TD42 and took the 4.3 diffs
- interior in pieces, missing stuff
- both of the tail lights damaged, LHS mirror damaged
- car has been unregistered for 3 years
- 3 rust spots, nothing major
- interior stripped completely as previous owner bought a DX TD42 and took velour seats and door trims

I picked one of the hottest week to do the conversion, but hey, it's TD42 and it's worth it :)

We have started with stripping GQ from all the good bits and pieces, removed engine, gearbox, stripped the interior apart from all the parts that I could possibly recover some of the cost.

I have booked in a UHaul car trailer for the 26th of December, but in the morning none of the terminals were working and I ended up getting a Tow truck to pick it up and deliver it the following day, so we had enough time to pull GQ apart and get ready for the GU to arrive.


Happy Days as the GU arrives just after lunchtime on the 27th, so without wasting time we started taking everything from the inside, to check what's missing. Since previous owner has removed cylinder head (cracked) and sold the gearbox our task was really easy. In the meantime I found a buyer for my GQ bullbar, both GU diffs and GQ LHS doors - $$$$ :)

[Mike_1]

After removing every possible useful bit we have proceed with cutting off the TD42 chassis engine mounts trying to save as much steel possible sacrificing the frame. The same thing happened to the ZD30 engine mounts, but this time we've tried to save the frame. So far engine and gearbox have been removed off the GQ leaving the old chassis sad and empty :(

[Mike_1]

On the following day while listening to the best tracks of AC/DC, having few cold one's we've removed GQ diffs and swapped them with the GU ones. Early that day buyer showed up and picked up GU diffs, GQ bullbar and LHS GQ doors.

Having parts gone, we've then continue with building GU, we have started with the GQ TD42 gearbox. It all looked like a pretty straight bolt on, except that we had to modify the centre tunnel in order to fit in GQ transfer case. Task is pretty simple, cut approx 10x10cm centre of the tunnel and the GQ TD42 gearbox fitted in perfectly. We've noticed that the GU ZD30 gearbox crossmember is exactly the same EXCEPT it has welded on spacers (approx 5-8mm) which makes gearbox sits a little bit lower. We've decided to use ZD30 gearbox xmember as having 4" lift kit makes gbox/axle angles smaller. Since we're transferring gbox/engine and diffs there was no need to change the tailshafts, they all fitted in perfectly with the correct lenght.

[Mike_1]

Just before the conversion has taken place I managed to buy off my mate used 3 core copper GU TD42 radiator for $300 and a brand new tail lights off GU3 on ebay for $50 incl. shipping - what a steal!
On the previous photos you can see ZD30 engine mounts cut off and patched up, later on they were shimmed and painted - they look like they have never existed!

PS: Before doing the whole conversion I have contacted RTA to find out if I need an engineers report or not and I was advised that since TD42 was an option in GU no report is necessary - I have confirmed that 3 times before proceeding with the conversion.

PS2: Please forgive me all my grammar mistakes and language as I'm a Polish citizen trying to have some fun in the aussie bush :)

[MudRunnerTD]

Looks great mate. Question? Did you just sell the 3.9 centre from the GU or physically remove the full diffs hub to hub and replace with your GQ diff?? I hope it was option 1???

[Mike_1]

I have sold GU complete diffs, including the 3.9 centres and installed GQ complete diffs.
The reason for that is:
- factory GQ rear diff lock - painful to adapt to a GU diff
- front diff has been completely rebulit 3 months ago :( - all the bearings, seals, both CV's
- GU diffs been sitting unused for more than 2 years - possible parts replacement in the near future

Based upon that I have decided to go with the GQ diffs not GU - time will show whether it was a good call or not.

[MudRunnerTD]

Bugger. Oh well it's done, would not have been my choice. The diff centers go straight in as long as the rear was not a H260.

The wheel track on the GU is wider and the front CVs are far far bigger and the Brakes!!! OMG The brakes!!! Soooo much better on the GU diffs. You should have got $1200 to $2000 for the pair of Diffs though.

I run GU diffs on my GQ and it is a common upgrade.

You will need the tie rod, drag link and he steering box off the GQ of a custom drag link with a GQ and a GU end on it as the GU taper is a slightly different angle.

[MudRunnerTD]

Running GQ diffs you will want a bigger offset rim or the wheels will be sitting well into the guards

[Mike_1]

I do have a mate that has got couple of the GU housings, so there should be no issue with changing it later on. As for the rims I'll need to see how the current one's go and decide later on. I simply couldn't afford to do everything at once, so time will show what else req replacing. It's a good start though.

[Mike_1]

My tie rod is an extra heavy duty one with a lifetime warranty for bending, custom draglink that fitted GU steering box perfectly. The only thing I need now is a GU 2000+ rear panrod bush and slightly longer panrod screws.

[MudRunnerTD]

So you took the tie rod from the GQ with the diff yeah? All good.

Yes the drag link will bolt up no probs But, the Taper angle of the GQ tie rod end on the drag link at the Steering box end is a different degree taper and will not "taper lock" which is not ideal. You can replace the tie rod end on that end with a GU one and your done. If you still have the Tie rod from the GU diffs then rip an end off it and fit it to your drag link.

[ckjonno]

Hi mike_1
This is the process I'm thinking about doing rather than fixing the dreaded IP failure.
Couple of questions
1. Who did you contact at the RTA?
2. Did you need an engineer inspection when you changed the engine mounts

Any help would be great

Cheers

[Mike_1]

Hi guys,
Sorry for being slack with getting everyone updated on the project progress, but I've been extremely busy at work. Recent upgrades: set of four 35x12.5x15 Maxxis Creepy Crawler tyres on a 15x8 sunnys46646

ckjonno: I've called RTA number and I was transferred through to the techincal support. I did it twice and spoke to two different RTA representatives. No one mentioned anything about getting eng cert for the engine mounts, looks like they don't care as long as the engine was an option for this model.

[Mike_1]

Since both of the diffs came out of the GQ and it has a factory rear locker (vacuum one) we are having a bit of a dramma making it working in GU. I bough GU difflock switch and GU difflock ECU module, but whenever i'm trying to engage the it, difflock lamp keeps on flashing on the dash and it doesn't actually engage the difflock. Both solenoids were tested OK, vacuum is OK, difflock is OK. Tried different ECU's and different switches - issue remains. When I tested the solenoids connection, I'm getting 12-14V (can't remember exactly how much) on one of the outputs, but when I engage it, there is no voltage coming out of both solenoids electrical wiring. Any suggestions?

[mudski]

Any suggestions?

Rip it all out an put an air locker in and be done with it....


Sorry thats all I got. :) Atleast you will know it will work.

[Faviles]

Hello

What did you dot with the speed meter? Mine it is just not working after a change from a ZD30 to a TD42

[TUR7LE]

Was there anything else that you needed of the gq