The 10-spline rear half-shafts (axles) that Land Rover slid into the axle tubes of their Series trucks are failure points of legend. I have always been curious how many of part #591378 or #591389 have snapped while exposed to my Series III’s lethargic 80 horsepower since 1974; I will never know.
I do know that since I purchased Eore in 1996 I have broken one axle. I do not owe this reliability to my mechanical sympathy, but to Great Basin Rovers of Utah and their 10 spline Series replacement axles. I will get back to discussing this great product but let me first discuss Land Rover’s engineering effort.
During the pre-internet dark ages, Land Rover information was shared at club meets and over canned tuna at remote border crossings. It was from the myths of enthusiasts - their travels, and their Land Rover tricksters - that I learned to always carry spare shafts, that after the pop 4-wheel drive will get you home and to carry a long metal rod to “pound out” broken half-shafts from the opposite side of the differential. My life experience provided some additional lessons.
My particular half-shaft popped under eucalyptus scented, California sunshine 3 blocks from my garage. Depressing the yellow knob engaged the front axle and motive power was restored. Given that the prior week was spent laden with camping gear and fuel while solo and southbound in Baja, Mexico - I decided the timing of this failure was get-us-home heroic. This, by the way, is a classic example of the required Land Rover owner glass-half-fullery. On to my contribution to Series Land Rover half-shaft knowledge.
My break required the removal of both axles, removal of the differential - and lots of lube, cursing and pounding to get the axle stub out of the differential. As predicted by Land Rover lore, my break did occur on the long shaft. My issue was the break left a small axle remnant embedded in the spider gear, and no amount of off-side, long-rod pounding would have ever dislodged it. My advice regarding the metal rod from the opposite side advice - do it right and remove the differential. Here are some additional thoughts:
It wasn’t until late 2001 that the ever expanding internet revealed the existence of both Great Basin Rovers (GBR) and their new Series axles. Vastly superior strength was promised, and by retaining the 10-spline count they were a simple, bolt-in replacement. Ever the skeptic, I made the decision to still carry spares on longer trips, and this revealed my one criticism of these half-shafts.
GBR made the decision to affix the drive flanges to their half-shafts. While this did eliminate a potential weak point, it also necessitated carrying flanges if using factory spare axles. For the gross vehicle weight obsessive, like myself, this resulted in the additional load of at least one drive flange. Admittedly, this is a minor gripe from a mechanical vehihypochondriac (defined in a May 12, 2016 blog post).
On to the praise… Since 2001 these axles have churned bull dust, wash sand and been subjected to thousands of miles of washboard roads in Baja, Mexico. They’ve endured the shock-loads of spinning, dangling wheels while finding traction in the red rocks of Utah, in the river beds of the Barrancas Del Cobre and while paddling mud in Guatemala. They have also pulled away from countless stop signs and Latin American “topos” while carrying heavy loads, suffered an off-road beginner, endured relationship tempers, picked-up a bride and hauled trailer loads of horse manure.
I consider surviving these past 20 years at the tire end of my right-foot proof of reliability. A 2020 inspection of the diff-side splines of my GBR half-shafts revealed no spline deformation or twisting along the shaft; I consider this proof of durability. Vist Great Basin Rovers for a full list of their drivetrain products.