Buying a used Toyota LandCruiser 75, 76, 78 & 79 Series

The Toyota LandCruiser has been the Australian bush’s favourite workhorse since Leslie Thiess (later Sir Leslie) introduced the first LandCruisers to Australia in the 1970s.

The 75 Series was introduced in January 1985, replacing the ubiquitous 45 Series. The existing petrol and diesel engines carried over into the new models.

Toyota offered well-sorted vehicles with the right spec' for most applications, but the base-model front seats were a pretty ordinary bucket-plus-bench arrangement.

Despite its working class vocation, the 75 Series was easy to operate, with all controls well-positioned and functional. The across-vehicle rear seat on RV models was a tad featureless and unsupportive, but vision was quite good from this rear perch.

The Toyota options list for the 75 was comprehensive: air conditioning, a second, 90-litre fuel tank (later made standard), electro-pneumatic differential locks and a snorkel, so many used machines are fitted with some or all of these.

In November 1989, the 2H pushrod diesel was replaced by the overhead-camshaft 1HZ 4.2-litre, rated at 89kW at 4000rpm and 271Nm at 2000rpm.

Optional, vacuum-operated diff locks were added to the specification. The factory diff locks can’t be retrofitted and still can’t on the 78/79 Series, because the diff-lockable axles, their internals and half-shafts are unique parts. The next upgrade was in November 1992, when the 1FZ-FE twin-cam, 24-valve petrol six was introduced.

At the same time, all the 75 Series scored four-wheel discs, complete with drum-in-rear-disc parking brakes, in place of the previous tail shaft drum brake. The diff lock actuation method changed to electro-mechanical.

In March 1995, the diesel was given a minor rework and a power increase, up to 96kW.

78/79 INTRODUCTION

Toyota upgraded the 75 Series to 78/79 level in 1999 with coil springs at the front end and longer leaves at the back. The petrol engine option was dropped. The existing diesel engine was upgraded and fitted with a high-altitude compensator, to reduce rich-running and oil contamination.

The engine was mated to an improved, lighter-shifting five-speed transmission and there was also a new clutch, with reduced pedal effort. The 78 Series was fitted with shorter-geared, 4.3:1 final drive ratios in the axles, to improve performance and top-gear flexibility.

The 78 Series' coil-sprung front end was derived from the 100 Series wagon range and incorporated larger-diameter disc brakes with four-pot callipers.

Rear leaf spring length on all 78 models was increased by 172mm, for longer wheel travel and improved ride comfort, and an anti-sway bar was made standard on Troop Carrier models. The leading spring hanger was positioned lower than the 75 Series hanger, to reduce the rear-axle steering effect inherent in leaf spring arrangements.

Low-pressure gas-charged dampers were fitted front and rear.

The 2002 year model 78 Series could be ordered with a lower compression ratio version of the 100 Series' turbo-diesel, minus that engine's intercooler. The 1HD-FTE diesel six put out 122kW at 3400rpm, with peak torque of 380Nm between 1400rpm and 2600rpm.

Because of the new engine's greater torque Toyota was able to use 4.1 final drive ratios on most models, with only the 11-seat Troop Carrier turbo-diesel model having 4.3:1 diffs.

The 78 Series ute had a 200mm wheelbase increase over the 75 Series and a 120mm increase in cabin length, for more interior space.

The five-stud wheel pattern introduced on the 100 Series was used on the 78/79 Series. Toyota claimed greater wheel clamping power from the new arrangement, which had thicker, 14mm studs and a larger-diameter pitch circle.

The 78 Series didn't receive any significant bodywork changes with the turbo introduction, but the previously optional snorkel was made standard equipment.

A new RV-grade cab-chassis was introduced, with bucket seats, carpet, remote central locking, power windows and aluminium wheels.

Internally the 78 Series looked little different from the 75, but the instrument panel integrated the auxiliary fuel tank gauge, rather than its previous location on top of the dashboard. The new panel had backlit electronic instruments, a digital odometer with two trip meters, and warning lamps for door ajar, fuel filter condition and, in the case of snorkel-equipped models, air cleaner restriction.

The factory differential locks and snorkel options were retained for the 78 Series, and front and rear bars, spotlights and a Superwinch were added to the options list.

V8 DIESEL INTRODUCTION

Toyota unveiled the long-awaited successor to the 78/79 Series in 2007. Toyota stuck with its policy of making as few changes as possible to its LandCruiser workhorse range. The aged, in-line diesel six couldn’t meet 2007’s mandatory Euro IV emissions targets, so was replaced by an all-new V8, common-rail-injected diesel.

The 4.5-litre V8 was under-stressed in the 70 Series, putting out a mild 151kW at 3400rpm, with 430Nm in the 1200-3200rpm band. These figures were improvements over the previous turbo six’s 122kW at 3400rpm, with peak torque of 380Nm between 1400rpm and 2600rpm, but they were not massive increases.

That was probably just as well, given the few changes that were made to the chassis and suspension, and the absence of any stability control or even ABS brakes.

A plus for the new engine was oil drain periods of 10,000km, out from the six cylinder’s 5000km.

The 75-78 Series ‘veed’ front end with its small grille opening was widened to accept the V8 engine with its much larger radiator. The front track was also increased, but not the rear. Aluminium-wheel models have nearly 10mm track difference between front and rear axles.

The V8 could pull taller, 3.91:1 final drives than the previous 4.11:1 diffs, but engine revs at legal cruising speeds were still too high (2600rpm at 110km/h) so fuel consumption was at best 12.5L/100km.

The standard offering of twin 90-litre fuel tanks continued on the new LC78 and 79, but the 76 Series four-door wagon had only 90 litres’ capacity.

This ‘new’ four-door 76 Series was a revived, repowered and slightly rebodied wagon, with live front and rear axles, marketed years ago in some markets as a Prado, but closer to being a four-door version of the Bundera, with leaf rear springs.

Toyota didn’t fit a wider cab to the new 70 Series, so the squeezy three-seat, bucket plus bench arrangement remained. The GLX ute models had twin buckets.
The interior and dashboard remained virtually unchanged from the old 78/79 Series, until the introduction of SRS airbags in 2010.

Already too-high pricing of the 70 Series was held in check, with the LC79 cab/chassis in the $53,490-$56,490 range and the LC78 Troopie ranging from $58,890 to $61,490. The four-door LC76 wagon was priced from $53,990.

Air con was an expensive $2640, but the double-diff-lock option was well priced at $2735.

USED 75 SERIES

The twin-cam 4.5-litre petrol engine was almost overkill in the 75 Series, while the diesel slogger was one of the best low-speed, off-road engines ever made.

For most used 75 Series buyers the diesel is the preferred engine, blending reasonable performance with acceptable economy around 12-13L/100 km. The big petrol engine drank like a sailor and usually returned no better than 16-20L/100 km.

The plus side of the crude leaf-spring equation was a suspension that was very reliable in tough conditions and easily repaired in the bush. What the 75 Series lacked in wheel travel, it provided in controlled chassis twist, so a well-driven 75 was very capable in demanding off-road conditions.

Leaf-spring suspension relegated the 75 Series to a rough ride on all but smooth blacktop or dirt. Since ride quality wasn't exactly the 75's strongest point, many used vehicles have various suspension mods intended to improve the situation.

The base-model 5.50x16 split rims are popular with cockies, councils, government departments and mining companies, but most recreational users fit widies and tubed or tubeless one-piece wheels.

The stock limited slip diff was weak in comparison with the Patrol's, so serious off-roaders normally opted for diff locks. The factory diff lock actuation was complicated, however, and there was often a delay in getting the locks to engage, which is why the design was progressively changed to full-electric operation.

The 75 Series engine bay had an unusual tapered shape, which caused some dramas for operators in hotter parts of the country. Airflow through the radiator wasn't as good as it might be, which wasn't a problem most of the time, but could be if owners extracted more grunt from the diesel engine by turbocharging it.

USED 78/79 SERIES

The LandCruiser 78 Series wasn't planned as a revolutionary development, but an evolutionary one. Payload capacity, off-road and rough-road ability, and powertrain and driveline simplicity were preserved.

Revised seats and the coil-sprung front end improved ride quality out of sight. Even empty, the Troop Carrier had balanced handling, albeit with a stiffer feel from the back end than the front. With a half-load in the back the ride was reasonable, even over corrugations.

The upgraded engine didn't smoke. It would cough up a blue puff on a cold morning, but the rest of the time it ran with almost a clear exhaust. That augured well for slightly extended oil service intervals, because the 78 Series didn’t dump as much soot into its engine oil as the 75 did.

On-road ability was enhanced by the additional engine urge and cog-swapping in the revised gearbox was much sweeter.

Toyota claimed a five per cent fuel consumption bonus for the 78 Series over the 75, but we were unable to measure the difference when testing the 78.

We tested the naturally-aspirated 78 Series against a factory-turbocharged, 4.2-litre Nissan Patrol GU and found that the Toyota wasn't far behind the Nissan, despite a significant on-paper advantage to the Patrol.

Off-road the 78 Series was a better performer than the 75 Series, thanks to greatly improved engine response, lower-speed gearing and better wheel travel front and rear. Ride harshness was noticeably less on rough surfaces.

Even the non-turbo 75 and 78/79 models were capable on-road solo vehicles, and there are many 1HZ 78/79s in the used market that have been successfully turbocharged.

The factory-turbo 78 Series had impressive performance and top-gear flexibility that the naturally-aspirated engine couldn't match. Highway hills that sent the naturally-aspirated model into fourth gear wouldn't force the turbo version out of fifth.

Because of the new engine's greater torque the 4.1 final drive ratio on all but the 11-seat Troop Carrier turbo-diesel model let the 78/79 lope along in fifth at 110km/h with 2600rpm showing on the tacho.

We found that low-speed, off-road crawling performance wasn't affected by the final drive ratio change, because the new engine had ample torque, even when the turbo wasn't spinning at optimum boost revs.

Toyota tuned the engine's torque curve to be almost flat from 1400rpm to 2600rpm, so off-road behaviour was very stable, with no sudden torque surges.

Used current-model, V8-diesel-powered models have a huge performance advantage over their six-cylinder predecessors, but could really do with a six-speed ’box to drop engine revs at cruising speeds.

MECHANICAL ISSUES

Mechanically, 70 Series lasted well, although the part time 4WD driveline was easily abused. Many working 70s spent much of their time in 4WD, even on hard surfaces, so transfer case and differential problems were common. Transfer case bearings and front tailshaft splines are prone to wear.

Swivel hubs, bearings and seals need regular attention, as do the gearbox lever bushes.

Rear disc callipers are prone to failure and the V8 seems to be a bit much for the old transmission, causing premature wear.

Later model front diff housings bend, like coil-sprung Patrol axles used to do.

After-market turbocharged 1HZ engines seem to last well, provided oil drains have been done every 5000km.