Outer Limits 4x4 Board

Been trying to find posts in regards to GQ conversions but couldn't find any so I might have to bore you all with a typical question.

I have a 2.8 turbo deisel GQ. Engine is fine but the gearbox is too high in first gear for heavy towing (3 Tonne).

Need to find out if the 4.2 Deisel gearbox can be bolted to a 2.8 Turbo Deisel engine or not. Or do I have to buy the 4.2 engine?

Cheers

4.2 is different to 2.8, you need to change. 2.8 and rb30 are the same

you have 4.6 diffs and around 4.3 first gear...are you saying its hard to get it moving in first? if so bad news is you already have the best gear combo...do u run big tyres daily?

jusrt saw ya post in the other thread, the 35s are killin ya that's why it goes SHlT in first

I'm aware of the tyre issue but it's not as bad a difference & plus I'm not prepared to go into the pits every day to change tyres as my crew is me.
I have 4.8 dif ratio. 3 tonne of towing will make any 4wd sweat a bit anyway. But with 4.8's & 4.2 DT & new G'box it will alleviate all of that I suppose.

Without a heavy load she purrs like a kitten & have no dramas running 35's

I have more than 200 kw at the wheels and first gear isnt fun on 35's with a car carrier, on 31's though you dont even know its there.

NutterGQ. What dif ratio are you running?

Had a few offers on GQ engines & are all out of my price range. Might have to drop down to a 4.2 Deisel from a GQ.

Zol changing to the TD4.2 is the best thing that i have done

know where your coming from trying to tow anything with the 2.8 motor.

My advise we be try and by a whole car that has good running gear as it will save ya lot of time effot and cash by the end as there are alot of little items that differ between the two engine gear box combinations.

im running 4.3's on 31's you cant even tell its on the back lol

Does anyone have experience in Knowing what the needs done on a conversion from 2.8 to 4.2 besides the obvious engine,gearbox & radiator?
Are there mounting conversions? Driveshaft diferences etc?

The engaine change is fairly straight forward. The gear box /transfer case is a stright swap, cross member hole centers are the same.

You will have to change pinion flanges on your diffs, clutch line is on other side of bell housing, radiator is different, power steraring pumps are different. If you leave your fuel filter where it is it will save you having to run fuel line to the other side of the engine bay.
You will have to fabrcate an adaptor for the RHS engine mount there is six threads cast in the block for the engine mount you only bolt up on four. I made a plate that picked up all six holes then drilled this to mount the eninge mount so in suited the chassis position. No need for any cutting or welding of the chassis.

The electrics are fairly basic as well, swap your oil and temp sensors from the RD28 motor. You can also do the same with the glow plugs as the two engines have different systems. this will just requier you extenting some wires. You will have some other little wireing changes to make but nothing to hard.
I just blanked off all the pollution? air sensors that were on the RD28 air cleaner.

to date ive had no problems and ive had the TD42 motor in almost a year.
I bolted on a turbo whilst i had the engine on the ground this would be a big plus if your going to tow a large boat.

Best thing i ever did. Keep your 4.6 diff gears and it will fly. If you buy another car as i stated earlier you will have everthing that you need then just sell off all the left overs.

Trump. that's great information.

I might have an option to buy a 4.2d Maverick cheap. Was thinking of installing the 2.8 into the Mav & take out the 4.2 then sell off.

Can the turbo be used from the 2.8 ?

Not kowing that much about turbo's, i would think that the turbo from the 2.8 wouldnt be big enough for the 4.2 engine.

I think i may have read a thread on here once before from someone asking the same question.

as long as the transfer cases are the same between GQ2.8 and GQ4.2 diesel, which i believe they are, you can run the 2,8 transfer case and not have to worry about swapping tail shafts and pinion flanges,
this is what we did on a 2.8 swap in a GU where we fitted a TD42t inplace of it,

in the GU we also found that the transfer case cross members were different, the rubber gearbox mounts we off by approx 20mm, so we had to swap out the gearbox cross member,

we also found the driver side engine mount was different, we didnt mod the chassis, we actually modified the mount on the motor to suit,

radiators were different,

like i said this was in a GU, but u still suspect it will apply to you in the GQ, as they run the same gearbox cross members as the GU series,.

i dont see the point in sperating the gear box and transfer case if what you buy is ok. It may only lead to extra work in the future if you dont install correctly.
The tail shafts on the 2.8 are smaller than the 4.2 would this mean that they may be stronger. Changing pion flangers would be far easier then changing transfer cases and give you a better end result IMOP.

The transfer case is easy to swap from the 2.8 gearbox to the 4.2 box
with Two difference.

The Tcase from the 2.8 has a extra lip on the gear casing for a oil catch.

Because between the 2.8 box and Tcase fills with Oil where as the 4.2 one dose not

So you will need the inside gear casing from a 4.2L transfer case and swap
it over and all will fitt.

The second difference is where the 4x4 gear lever joins the transfer case
That short joining rod is not the same as the 4.2 lever

Easy fixed with one bolt .


And one more up side to keeping the 2.8 t case is your speedo will be the same

Does anyone make the engine mount pre-fabbed?


This is great information guys. Thanks very much. It will help ease the pain once the time comes.

Ok. I am one step closer to getting it done.

I just picked up 4.2 Deisel Maverick. Will be doing some research before I pull the engine out & have parts everywhere.

Next step is maybe looking for an after market turbo....be it second hand or new.

Can anyone tell me how big I can go with this engine in turbo size? Garett seems to be the recommended but am very uninformed at this point.

Cheers
Zol