Toyota Landcruiser HDJ100 to 105 Series Swap

Build Video:

Note: The work on the car discussed in this write-up and the write-up itself is the work of my brother Tom. I am just a name to post it under. 

Prologue: Aspirations, Naturally

Alright, so if you're mentally ill like me then you know off the top of your head that the only 4WD Toyota built for the Australian market that had the golden trifecta (coil springs front and rear, solid axle front and rear, and turbo diesel) is the humble 1HDT/FT 80-series… So great, just buy one of them and be on your way.

No, you see the proceeding model- the 100-series Landcruiser, holds a very special place in my heart, and I don’t think I’d be complete without one to call my own. Not only is it the car that my old man has owned for as long as I can remember- with which he has racked up over 400 thousand ks on some of Far North Queensland’s toughest outback roads with little to no complaints- but also served as my first car and entry into the 4wd scene. (Un)fortunately, since getting my hands on this HZJ105 non-turbo, fleet-spec (affectionately named in the community “pov pack”) variant of the legendary Landcruiser in 2020, there has been no interest in branching out to other 4x4 makes/models since as I am truly sold out to the 100-series for life. 

Chapter 1: Smiles per gallon, not miles per gallon

Now, as good as the HZJ105 served me, the NA 6cyl diesel didn’t exactly fit the touring spec balance that I so much desired. Mostly that was it's failure to reach over 90 km/h on the flat. Some nice-to-have features also missing from this model, such as cruise control, electric windows, and central locking had me reaching dangerously for the accelerator pedal brick on some particularly sleepy 12 hour drives. To solve this, enter the FZJ105 GXL. 

Sporting Toyota’s 4WD answer to the 2JZ: the mighty 'forklift engine' petrol 1FZ-FE. Purchasing one of these interstate, during the peak of COVID, might seem absurd to everyone who was not endlessly scrolling marketplace at this time, but believe it or not I managed to pick one up with reasonable mileage for $11.5k. Now I had all the bling, and all of the electronics that were missing before, but at a cost…  You see, what everyone in the community will be quick to tell you is that the FZJ105 has high fuel consumption. I chose to ignore this and found it out firsthand instead.This was not helped after I increased the tyre size, lifted it, and threw a boxy slab of a rooftop tent on it. Sure enough, at highway speeds with AC (which was also another major upgrade from the HZ), 22L per 100km… Not only that but someone had once decided it would be a good idea to bbq-convert this car. So after removing the 90kg LPG tank from under the rear I was unsurprisingly met with an empty space where the sub tank once lived. So that was that, 80L main tank and 22L per 100- you can do the division yourself- it doesn’t exactly make for a ‘tourer’ by any meaning of the word in this country. Despite the shortcomings, I inevitably drove this car to its limits, all around the country. While the wallet grew lighter, the car just proved itself time and time again for the almost 45,000 ks I drove it, through all conditions and even a serious accident on a 4WD track (but that’s another story), and onwards. 

Chapter 2: The question

Now, someone at Toyota decided that Australians can’t have the best engine ever made with a solid axle, coil-all-round, wagon. And since someone once said solid axle is better and everyone has agreed ever since, several people didn’t stand by this decision and started ‘frankensteining’ the 1HDFTE engine all over the place. Right now, you can go on carsales search by 1HDFTE 100 series, sort by price High to Low, and there’s a good chance you may just see one of these ‘unique’ creations. Likely for an understandable $60-70K (entry level given Toyota 4WD prices, but do remember these are at the very least 20 years old..). This price tag makes more sense when you look further (as I spent many a late night doing) into the price of JUST the 1HDFTE engine- fetching up to 20k still. However, to my untrained mechanical eye, and the information in front of me, it still didn’t add up. I fully understand that an engine conversion is no minor mechanical feat, but this is physically (and by legal definition in SA) a factory option engine for this vehicle, so why does adding a $20k engine to a $10-15k car make it a $65k car?

Chapter 3: The answer?

I touched on this before, but my FZJ105 had some scars, an unfortunate incident with a power pole in the front passenger quarter meant I had to weld an entirely brand-new-second-hand internal piece in, and replace the quarter panel and bonnet. Despite this, I continued to drive it for over a year after until it was no longer my daily, and the real project could begin. Given this poorly repaired damage, and further extensive research, I opted to attempt a full chassis swap to a similar variant of 100 series- the HDJ100. This may sound more complicated than an engine swap, but I had the undamaged chassis and immediate access to a 2-post hoist, so this choice gave my existing 105 a new lease on life. This decision also meant I had a ‘parts’ car of sorts in the donor , a bit of a sad concept given both cruisers drove perfectly fine before, but I did feel a lot better about it knowing the condition of my own FZJ105 repairs. Finding the donor cab and engine remained difficult, long nights scouring marketplace in hope until finally I found one- just around the corner, and pure grandpa spec- perfect. With a measly 468k on the clock (just broken in some would say) I opted to daily the new (to me) HDJ100 cruiser to ensure it wasn’t too good to be true for the price paid, and sure enough it passed with flying colors. On to the build… 

Chapter 4: The build

With a fairly daunting task ahead I got straight into it. Starting by essentially disconnecting anything that joined the body to the chassis or engine of the FZ 105. In addition to the obvious things (radiator, AC system, brake lines etc) there were a few wiring loom parts that I only found out were connected once the hoist forcibly did the job for me… Relatively speaking though, this was all simple work and only took me half a day or so taking it slow. Next, after removing the wiring loom itself through the firewall, and the body mount bolts, the cab lifted straight off from the chassis and engine without too much fuss.

Immediately it was on to wire wheeling the chassis. As previously mentioned, it has had a fair life thus far, a few hours on the wire wheel, a few coats of Septone 'chassis black hammer finish' and some fish oil and it looked brand new. Preventative maintenance on diffs, axles, brakes and anything steering related would have to wait until the whole thing was back together, mainly due to the budget disappearing fast but really there was no major need. The mighty 1FZ found a new home too, ratcheted on a pallet in a very 'she'll be right' farmer’s trailer. I still wonder if they made it up the southern expressway... It was somewhat sad to see it go- whilst largely condemned by the 100/105 series Landcruiser community, the powerhouse had shared many a happy and many a sad story with me. 

The dream started becoming real when the chassis was fully painted and essentially back to brand new. This project wasn’t just a routine service but actually an overhaul of the car itself- bettering two mediocre cars. Splitting the HDJ100 off the frame was essentially the same as earlier. Although knowing the IFS torsion bar style suspension was destined for scrap metal sooner or later, I was a little harsher with this one. The body of this was, as previously mentioned, quite run in (468,000 kms..) however, you really wouldn’t know it. Whilst most of these cars are plagued by red dirt, this one had minimal. And given the overall modifications done to the car fit the general description of ‘grandpa spec’, one could draw such conclusions about all previous owners of the car. With the new body separation from the chassis, I had my first walk around look at the 1HDFTE, indisputably a legend of 2000s turbo diesel engines. Still highly sought after for various reasons, these could push up to 350-400hp with stock internals or reliably push 200hp day after day without fail. For me, I just wanted a balance of fuel economy, torque, and reliability, so it was just reconditioned injectors and gasket overhaul. This was easy enough once it was out on the engine stand, a place where it sat for quite some time. 

 

 

Here and there I kept up-selling myself on various things- a 3-inch exhaust, DIY engine bay sound deadening, a full interior removal and clean… I wouldn’t exactly say the build spiraled, but there just always seemed to be something else that could be done. Finally I’d had enough and just wanted to drive the damned thing… So the FTE went on the 105 chassis, surprisingly easily with some HZ engine mounts from a coaster bus. Following that was the H151 5-speed manual gearbox, something that is shared between the FTE and the FZ and a highly regarded manual transmission. This included a brand new NPC1300 clutch, the first time I’ve ever done a clutch and I was blessed with being able to do it from above, not below. The rest of the build was pretty simple, the body lined up perfectly with the chassis, something I wouldn’t have started this whole conversion if I didn’t have complete confidence in. The ECU and wiring loom was reunited with the engine and after priming the system it just turned over and went like it was just built. My few years accumulation of random 4x4 accessories went back on and it was essentially the same car from the outside, minus the scars from the accident and now picking a heavier, darker brew at the local pub (servo), and indulging in it more sparingly, much to the delight of the owner. 

First Drive.

Chapter 5: The future

8 months later

Essentially, I got what I wanted from this project. The build has now tested itself in the sand and, more recently, the mud. Whilst I achieved what I wanted, much is left to do, no 4WD is complete without a liveable drawer system in the rear, electrical system to boot and steel protection all around, and of course whatever else social media (and my most recent endeavor into the industry of bespoke and expensive 4WD builds) persuades me that I NEED on my car.

Until the funds present themselves for these upgrades, this is how it will sit. In the driveway, waiting to be outdone by a 90s lifted Magna wagon or something… who knows? 

If you've read this far, thank you. I'll use the opportunity to plug my small business. Currently I'm working to fix most of the common breaks on 100-Series Cruisers. Mostly the AC panel LEDs, window buttons, and a few other things. If you have a cruiser don't hesitate to contact me.

https://lcelectronicrepairs.com/ 

I also made a full time-lapse style video of the build. Check that out at the top of the page.