4WD MODIFICATIONS - POWERTRAIN
This Dana 60 axle variant is a solution to the Toyota 70 Series’ narrow-rear-axle-track problem, as well as a way to increase rear axle load capacity.
Dana Australia has released a locally designed and manufactured Ultimate Dana 60 rear axle kit for LandCruiser 70 Series vehicles. This wide-track rear axle not only has the same track as the front axle – something Toyota couldn’t be bothered to achieve – but is also said to be much stronger than the standard axle.
Dana is the best-known producer of 4WD axles in the USA.
When Toyota released the V8-powered 70 Series in 2007 the coil-sprung front axle had to be given wider track, to fit the fat V8 into a space desgined originally for in-line sixes. However, did Toyota match the front stance with a wider-track rear axle? No, the company retained the existing axle, making front and rear tracks mismatch by up to 100mm.
If Land Rover had done it the 4WD community would have derided the poor old Pommies, but Toyota – being Toyota – got away with it.
A coil-sprung front and and a leaf rear had given the previous 78/79 Series weird handling to start with, but the addition of V8 grunt and a wider-track front axle made the front end laugh at the rear in tricky situations.
Owners took matters into their own hands and many fitted wheel spacers to widen rear track. Spacers are illegal for road use. Others had their rear axles modified.
At Dana Australia an engineering team set about rectifying the situation and the result is a replacement differentiial, axle and propshaft kit. When launching the new kit in March 2016 General Manager, Dana Aftermarket, Brad Wolstenholme, said:
“We are now able to provide a fully tested alternative, backed by Dana’s extensive engineering team and supported by a 12month / 30,000km warranty.”
The new rear axle is supplied as a complete aftermarket bolt-in kit. It has been designed, tested and certified by Dana Australia’s engineering team, and is being manufactured by Dana in Melbourne. The complete kit includes the axle, heavy-duty suspension brackets, axle shafts and all installation hardware.
A new heavy-duty propshaft has also been produced by Dana to suit all LandCruiser 70 Series variants.
Major features of the new axle include 95mm-wider track, increased oil capacity, higher axle load rating, heavy-duty suspension bracketry, heavy-duty cover plate and a Harrop-Eaton E-Locker, driver-controlled locking diff. The design retains original equipment brakes, hubs and wheels.
The Ultimate Dana 60 retains Toyota’s fully-floating axle design, with the bearings on the outside of the axle tube, so that rear axle weight is carried by the housing, not the half-shafts. However, the forged 1541 steel alloy half-shafts are larger diameter, 30 spline axles.
The diff has a heavy duty 9¾” (248 mm) ring gear, nodular iron cover and the axle tube is 90mm diameter, with 10mm wall thickness and heavy-duty suspension brackets.
The 70 Series Ultimate Dana 60 axle is available from selected Dana stockists. The official list price is higher, but most re-sellers are quoting $9-$10,000 for the swap-over job.
An alternative to the Dana replacement axle is the Tru Tracker, Australian-developed conversion kit.
Real world testing
One of the OTA Team bought a Dana 60 kit for his LandCruiser 76 Series tow vehicle and has been testing it for the past year. The axle and upgraded rear leaf springs have now done
25,000km of bush driving, towing a dual-axle caravan with a loaded ball weight of 320kg.
He already had a GVM upgrade on the 76, but that didn’t prevent the standard rear axle from being overloaded: it has only 1820kg capacity. The other 70 Series models with fully-floating-hub rear axles have 2360kg capacity.
Using the Victorian VASS system, after fitting the Dana axle, he had GVM increased to 3500kg, from a standard 3000kg, making the loaded vehicle totally legal.
The Dana 60 fitment doesn’t confer the same load advantage to 78 and 79 models that already have 2360kg capacity, but it does widen the rear track and that widening has conferred great stability when towing with the 76, according to our OTA Team member.
The Eaton-Harrop E-Locker is also much quicker-acting than the optional Toyota rear diff lock and can be used in 2WD and high range 4WD, unlike the factory lock that operates only in low range 4WD.
We reckon that Dana Australia needs to develop a Dana 60 kit to suit the coil-sprung rear end of the 200 Series, increasing its rear axle capacity from a standard 1950kg to 2400kg. The 200 Series is the most popular towing wagon in the Australian 4WD market and many of these vehicles have overloaded rear axles, even after GVM upgrades.