1HZ 105 series auto: Simpson Desert realistic?

Good Morning.

I'm planning a winter Simpson crossing (QAA + French lines) as I loved crossing last year in a friend's ute. Haven't decided on a vehicle purchase yet.

I'm just wondering if the ~2437kg kerb weight of the HZJ105 automatic will handle the dunes in the Simpson or whether we'll likely have to winch with a ground anchor even whilst aired down to ~15PSI.

It'll just be two of us travelling with all the usual equipment on board, trying to pack as light as possible but bringing along the necessary essentials and spares.

If I'm expecting too much of the 1HZ's 96kW and 285Nm of thumping glory, I'll get a 4.5L petrol 80 series with the ~160L replacement sub tank instead. Perhaps even a 3.4L V6 Hilux dual cab auto with jerry cans in the back would suit. Automatic is required for the missus.

I can plan the trek west to east to make it easier on the HZJ105 if people think it'd be worthwhile?

Thanks for your time.
Back Expand Un-Read 2 Moderator

Reply By: Les - PK Ranger - Thursday, Jan 18, 2018 at 14:02

Thursday, Jan 18, 2018 at 14:02
Ben, any of those will do it easily.
Just pack sensibly, take only what you need, spares you can actually use / fit yourself.
You might not make the hard climbs on Big Red, but will be fine . . . you will soon learn how to drive it, low or high range, gears, revs, speed etc, after you get into it.
The good thing about west to east is is the dunes increase as you go, so you can pick up the driving method steadily.
Also you'll be lighter the further East you go and be less to get over the bigger hills in the east.
It'd be good to do it with another vehicle along for support, but if worse came to worse, you would soon have someone come along the main lines that could give you a snatch over if needed.
AnswerID: 616170

Reply By: Member - Boobook - Thursday, Jan 18, 2018 at 14:08

Thursday, Jan 18, 2018 at 14:08
MY friend has naturally aspirated 100 with about the same power figures. He'd never driven on sand and doesn't do a lot of 4wding. He was the only one who didn't get stuck once on 2 crosings of the Simpson. Just let your tyres down to 15 or so and you will be fine. Get the diesel.

AnswerID: 616171

Reply By: Allan B (Sunshine Coast) - Thursday, Jan 18, 2018 at 14:12

Thursday, Jan 18, 2018 at 14:12
Hello Ben,

We haven't driven a 100 Series across the Simpson but have crossed it many times in our 1HZ troopy. It has become a shortcut to the Western Deserts for us. The crossings have been without problems although we did need to drop tyre pressure down from our usual 18psi to 15psi on one late afternoon. We carry 270 litres of diesel, 120 litres water and a heavy load of supplies and support gear for our remote trips so the Troopy is right up to 3,600 kg.
On that basis I think you would have no problems in the 105.

As to the direction of travel, we go both ways on our treks and really do not notice any difference in dune difficulty. There is no problem running at 18psi as typical speed over the dunes is 40kph max. with maybe 80kph for short distances across the occasional swale. A Ranger I spoke to once at Dalhousie said that he runs at 15psi all the time.

As for being an automatic transmission, although I am manual I understand that an auto is even preferred for the dunes.

It is extremely unlikely to need a winch crossing the Simpson, or anywhere else in the deserts. By the time you add the weight of a winch plus that of a ground anchor you are increasing the weight of the vehicle to the point of making it more likely to get bogged. I carry XTrax's but have never needed them. At least they are lighter than a winch.

My Profile  My Blog  My Position  Send Message

AnswerID: 616172

Reply By: Member - Stephen L (Clare SA) - Thursday, Jan 18, 2018 at 14:33

Thursday, Jan 18, 2018 at 14:33

Any of the above will do it with ease.

Depending on what time of the year and desert conditions can have a major influence on driving conditions. If you are having trouble, then drop your tyre pressures down lower. We have found that in nearly every case where we have seen people that struggle up dunes and cutting the hell out of the track, they have far too high tyre pressures and have no idea on takng it easy and low tyre pressures. On one trip we could hear a group in front of us that we're on a paid Tag Along Tour, and all vehicles were have problems get over the what I call easy dunes. Then their tour leader said over the radio, try dropping your tyres down to 35psi

I was then approaching the group and I could not help myself and gave their leader a lashing over the radio. I told the last two vehicles to sit tight and I will help them get over the dunes. One of the Troopies was running 50psi and I explained what to do and not take any notice of the group leader. We dropped both vehicles down to 18psi, told them they do not need speed and both vehicles then walked over the dunes with no trouble what so ever.

Over the years, we have driven it from powder fine dry sand that required quite low tyre pressures of around 12 psi, to compacted damp sand that was like driving on concrete.

As you know you are only driving slow and the key to any drive in the Simpson is tyre pressures.

Enjoy your return trip.

Smile like a Crocodile

Lifetime Member
My Profile  My Blog  My Position  Send Message

AnswerID: 616173

Follow Up By: Member - McLaren3030 - Friday, Jan 19, 2018 at 11:40

Friday, Jan 19, 2018 at 11:40
Couldn't agree more Stephen. Tyre pressure is the answer to sand driving. Have crossed the Simpson West to East in 2016, and will be doing it again East to West in April of this year. In 2016, tyre pressure was 26 psi, in a 76 Series Landcruiser, only had to back down one dune. For Big Red, dropped to 22 psi. In hindsight, I should have dropped to 20 psi at the beginning. Will be using this (20 psi) as my starting point again this year.


Lifetime Member
My Profile  My Position  Send Message

FollowupID: 887481

Follow Up By: Member - Stephen L (Clare SA) - Friday, Jan 19, 2018 at 14:03

Friday, Jan 19, 2018 at 14:03
Hi Macca

Having crossed the Simpson many times, our prefered direction of travel is East to West and the steeper east face is more of a challenge, but with low tyre pressures, it is an easy drive.

Enjoy your next visit.


Smile like a Crocodile

Lifetime Member
My Profile  My Blog  My Position  Send Message

FollowupID: 887486

Reply By: Mikee5 - Thursday, Jan 18, 2018 at 14:51

Thursday, Jan 18, 2018 at 14:51
Hi Ben, I have crossed the Simpson in a manual HJZ105. No problems, just choose the right gear, low 3rd was best for us travelling slowly. I only had to back down two dunes, both times was because of my inattention, not the vehicle. Filled at Oodnadatta plus an extra 60 litres in 3 jerries. By Birdsville the tanks were close to empty but didn't need the extra fuel. You should take extra anyway for contingencies. My tyres are 235.85.16 skinnies on 18PSI, could have gone lower if needed, no high revving or screaming the engine needed. Remember explorer Len Beadell did much worse country in a 4 cyl Landrover, power isn't everything.
AnswerID: 616174

Reply By: BenFraser747 - Thursday, Jan 18, 2018 at 15:36

Thursday, Jan 18, 2018 at 15:36
Thank you very much for the information and sharing your experiences. I'll talk it over with the minister of cuddles and finance.

AnswerID: 616177

Follow Up By: Member - McLaren3030 - Friday, Jan 19, 2018 at 11:45

Friday, Jan 19, 2018 at 11:45
Should that be War & Finance ??


Lifetime Member
My Profile  My Position  Send Message

FollowupID: 887482

Reply By: Member - Andrew & Jen - Thursday, Jan 18, 2018 at 16:40

Thursday, Jan 18, 2018 at 16:40
Hullo Ben

The auto trans will be working hard at times, especially in hot dry sand after noon.
The trans temps could therefore get quite high, enough to trigger the warning light, especially as air flow through the trans cooler and around the trans is markedly less at slower speeds..

The use of the transfer box in conjunction with the auto's full range of gears will ease the strain on the trans considerably and result in significantly lower temps (and greater efficiency?)

Low 1st can be a pain at times if the trans wants to sit there until a higher speed so I use the facility on the trans to start in 2nd and only override it occasionally as needed.

AnswerID: 616178

Follow Up By: BenFraser747 - Thursday, Jan 18, 2018 at 16:50

Thursday, Jan 18, 2018 at 16:50
Thanks for the response, Andrew.

Do you have a 1HZ powered auto? I understand that frequent shifting of the auto causes them to heat up quite a lot. Locking out 1st gear to take off in 2nd may prove to be a useful suggestion. Thank you very much!

FollowupID: 887461

Follow Up By: RMD - Thursday, Jan 18, 2018 at 18:23

Thursday, Jan 18, 2018 at 18:23
I think Andrew means staying in 1st may be the option as it means an increase in engine revs, lighter load of the auto and less slippage of the torque converter, which develops lots of heat (when transferring high torque) which is then being delivered to the engine cooling system.
The engine running lighter load and faster revs means the cooling fan is shifting more air which IS the only way engine coolant and auto heat is expelled from the vehicle.

A fan assisted auto fluid cooler would be a very sensible addition to your vehicle in such circumstances.
If the cooler fan or additional fan also flows air over the transfer case and clears heat from the underside of the vehicle that will also assist the engine cooling system.
Taking off in 2nd or holding it in 2nd may not be applicable as it causes more slip to get going or keep going.
FollowupID: 887463

Follow Up By: Member - Andrew & Jen - Thursday, Jan 18, 2018 at 18:54

Thursday, Jan 18, 2018 at 18:54
Ben, I have a Series 80 FT auto. Wrt 1st/2nd issue, what I am saying is that when using low range, if I don't lock out 1st and make it use 2nd, it will hang in 1st when starting off and only shift to second when it reaches ~2800 rpm - too high and that torque not needed! Starting in LR 2nd is not an issue for slippage/heating. I usually only use LR 1st when I need to negotiate very rough terrain at low speed.

Secondly, as you get used to the vehicle and conditions, you will find that a quick foot off, then gently on again of the accelerator will encourage the trans to shift up and lock the torque convertor. As RMD mentioned, the convertor generates a lot of heat under load.

As I mentioned, I often use low range in steep conditions, not just for braking on descents but up hill as well even though not necessary to get up the hill. Why? Because monitorong the gear box temps has shown me that this keeps the temps down around 65 to 75C cf 125+ in high range.

I hope this clarifies my original comment.

FollowupID: 887464

Follow Up By: gbc - Friday, Jan 19, 2018 at 06:30

Friday, Jan 19, 2018 at 06:30
I’ve found the same. I am lead to believe that very few (amaroks do) gearboxes will lock out lower gears in high range because they are designed to slip to enable smooth gear changes. Driving in lower gears high range creates heat - lots of it.
If you can run in high gears in low range your car will thank you for it. I did most of the French line in low range in an auto Colorado just poking along.
Amaroks are a casing point. Because they don’t have a transfer case they had to design an auto that can lock out low gears to make it cope with slow off-road work.
FollowupID: 887471

Reply By: dirvine - Thursday, Jan 18, 2018 at 21:39

Thursday, Jan 18, 2018 at 21:39
I have done the Simpson both ways in a Great Wall X240. 100kw and 200NM. I only enguaged low range and 4WD on Big Red on the West to East leg. Most of the time I was in high range 2wd but with rear auto locker. So you are way over powered to do the trip. Just lower tyre pressures!
AnswerID: 616185

Follow Up By: Allan B (Sunshine Coast) - Thursday, Jan 18, 2018 at 22:08

Thursday, Jan 18, 2018 at 22:08
Dirvine, why do you remain in 2WD instead of using 4WD? It is there to be used. It will do your vehicle no harm to use it.
Traversing dunes in 2WD is a recipe for spinning wheels and gouging the track.

Diff lockers are little advantage in sand. If a wheel is losing traction, it is a safe bet that the other wheel is very close to also losing traction, so the locked diff will be of no benefit. Furthermore, a locked diff will churn the sand more on those crests that require sharp turns at top.
Lockers are of benefit in situations of rocks and washouts where one wheel lifts into the air.

My Profile  My Blog  My Position  Send Message

FollowupID: 887469

Follow Up By: dirvine - Friday, Jan 19, 2018 at 08:16

Friday, Jan 19, 2018 at 08:16
Allan, car had auto locker on rear so I did not have an option. Front had a torsen type locker (only one available for a GW). These lock up the more you put the boot into the car and then it becomes hard to steer. As a result I found it easier to use 2WD. Given the lightness of the car and the lack of power I hardly can spin wheels. If at anytime I had felt it spinning I would have hooked 4wd. The issue is people with normal 4wd's do not understand how these lockers work and what you have to do to make them work for you, I was with a well known 4WD club and they were amazed at how easy my car went up and over. None of them (many very experienced drivers) commented that I was destroying the track or that I was spinning wheels. Many others however were...... and in mainstream brands.
FollowupID: 887476

Sponsored Links