Timmco 32 Spline Upgrade for Standard Land Rover Rear Axle
By TIMMCO
Timm Cooper's reasons for developing this conversion stemmed from his experiences in the mid-1990s. As he became more aggressive in his off-roading, running 35" tires on one of his Rovers, he frequently broke 24 spline axle shafts. Even custom chromoly shafts twisted and broke under the strain. His 1959 Series II 88", equipped with 32" tires, also occasionally suffered broken 24 spline shafts, as he was admittedly hard on his equipment. To accommodate larger tires, Timm began swapping axles, experimenting with the "legendary" Dana 44s, which proved inadequate, before moving to 35 spline swapped Salisburys and custom-shafted ENV units, which performed reliably. When revisiting Rover-type axles for lighter builds, he noted that while he never damaged the ring and pinions, he consistently broke axles, carriers, and ring gear bolts. Timm concluded that with proper ring and pinion selection and setup, using shafts larger than the 1.240" 24 spline could enhance the reliability of Rover-type axle assemblies.
Additionally, Timm realized that rock crawling in America is very different and requires beefier equipment than is needed for winch challenges and hill/rally racing in England. In rock crawling with a locking differential, very often one axle shaft is tasked with transmitting 100% of the torque from the ring gear to one tire under load, while the tire on the opposite axle shaft hangs dangling free in the air. This is where the chromoly 24 spline shafts often fail spectacularly, shattering and severely damaging other axle components. Timm’s decades of experience building trail vehicles show that the Rover ring and pinion strength, in a properly spec’d and set up unit, can make really good use of the larger 32 spline shaft configuration. Timm emphasizes the critical importance of a properly spec’d unit, which includes a ring and pinion selected for optimal tooth strength and maximal mating surface, high-quality ring gear bolts, “pegging” (thrust bolting) the differential housing, and an overall diff build setup not just according to general guidelines but optimized for the demands of actual off-road use.
BENEFITS:
(REAR axle 32 spline conversion)
- Significant increase in both strength and fatigue life of axle shafts above and beyond upgraded 24 spline aftermarket shafts
- Eliminates wear prone separate drive flanges, reducing drive train backlash.
- Upgrades to 15 bolts on axle drive flanges, tripling strength of this well known failure point.
- Upgrades to a larger, stronger chromoly rear spindle.
- Upgrades to larger, stronger wheel bearings with greater load capacity.
INCLUDED:
Although this kit is essentially ‘bolt-in’, it does require the Ashcroft locker to be disassembled, the carrier journals bored out for the larger shafts, and then reassembled. If Timm sets up your differential all of this will be done for you and you can just bolt everything in place using our instructions… and then hit the trail!
- 2 Spindles
- 2 Axle shafts
- 2 Wheel hubs
- Bearings and seals and hardware
- Custom bushings
- 32 spline side gears
NOTES:
-
This upgrade is only compatible with Ashcroft air lockers which have a casing made of billet steel and are the strongest on the market, particularly in the critical ring gear support flange area.
- If you arrange to purchase the Ashcroft locker from Original Iron along with the 32 spline upgrade, Timm will personally dismantle the lockers and build them up to ensure proper fastener torque and consistent application of thread locker on all critical fasteners.
About TIMMCO
TIMMCO products are designed and manufactured by renowned Land Rover builder Timm Cooper. With his more than 35 years of experience building custom, high-strength vehicles, Timm has unique insights into the demands placed on off-road vehicle components, as well as decades of designing and manufacturing parts that are more than up to the task of the toughest trails. You will not find stronger, better made components for your vintage or late model Land Rovers.