Weak Link: Plastic Drain Plug
Models Affected: '99-'04 Discovery II
What Happens: We don't mind plastic in our cupholders, but it has no place in differentials. The bean counters at Rover decided to save a few bucks and use plastic differential plugs on the D II axles. The same plug was also used in Discovery and D II radiators, virtually ensuring leaks given enough time.
Sturdy Fix: Great Basin Rovers stocks brass plugs to replace the plastic diff and radiator plugs. The new plugs feature an O-ring for proper sealing, they don't rust, and they're soft enough that they will not cross-thread the factory components.
Contact: Great Basin Rovers
Weak Link: Front CV Joints
Models Affected: '95-'99 Discovery I
What Happens: Land Rover CVs are prone to breakage, particularly when the front end is bound up and turned to the steering stops. The factory CV is 28 mm and 32-spline, and judging from the metallurgy, appears to be constructed from recycled aluminum cans and scrap metal.
Sturdy Fix 1: A bolt-in CV made from cryogenically stabilized aviation-grade alloy steel is available from CV Unlimited. The internal parts have been heat-treated to withstand the stresses endured off-pavement, and critical components are crafted from 300M.
Sturdy Fix 2: Rover Tracks has developed a kit that allows you to retrofit Longfield 30-spline birfields and axles from a Toyota into your Rover front axle, and even a Toyota pickup third member for additional strength. You already run a Buick engine, so there should be no shame in running Toyota axle components.
Contact: CV Unlimited, Rover Tracks
Weak Link: Door Sills
Models Affected: All
What Happens: As if the plastic diff plugs were not enough, the powers that be at Land Rover went so far as to use plastic rocker panels below the doors. While we appreciate that these will not rust, the plastic won't fend off shopping carts, much less rocks or other trail obstacles.
Sturdy Fix: 3/16-inch-steel rocker guards are available from Rovers North to protect the doors and rocker panels. The rock sliders offer an easy bolt-on installation, factorylike fit and finish, and even feature a built-in jack point.
Contact: Rovers North
Weak Link: Rear Upper Shock Mounts
Models Affected: '94-'99 Discovery I
What Happens: The rear suspension of the Discovery is an excellent design, but the shocks limit articulation potential when in stock form. More droop is possible if the shocks were not inhibiting articulation.
Sturdy Fix: Longer shocks require new upper mounts in order to provide more space between the upper and lower mounting points, and thus a longer shock. Rock Ware produces shock mounts that are built from 1-inch, 0.120-wall tubing and mount in the factory location. The new mounts allow the use of 12-inch-travel shocks and do not require brake-line or bumpstop modifications.
Contact: Rock Ware
Weak Link: Rear Axleshafts
Models Affected: All
What Happens: Even with the full-floating design, early Discovery I models are not exempt from rear-axle breakage. The axleshafts, at 32 mm and 24 splines, are comparable to a Dana 35 in terms of strength. The semi-floating shafts in Discovery IIs are even weaker. Once the differential has been upgraded to a limited-slip or locker, the axleshafts become the weak link in the chain.
Sturdy Fix: Great Basin Rovers manufactures heavy-duty axleshafts that are made of aviation-grade chromoly. These shafts are available for both the Discovery and D II and offer bolt-in installation while being significantly stronger than stock.
Contact: Great Basin Rovers
Weak Link: ABS Sensors
Models Affected: '99-'04 Discovery II
What Happens: Once you have lifted your Discovery II and modified the suspension for more wheel travel, the ABS cables can become impromptu limiting straps. Ripping off an ABS sensor is a dangerous (not to mention expensive) predicament. Additionally, the traction control is tied into the antilock brakes, so if you lose your ABS, you lose your traction control as well.
Sturdy Fix: Plug-and-play ABS extensions are available from Slickrock Fabrication for considerably less cost than repairing broken ABS components. The extensions are manufactured by WABCO, makers of the factory ABS on Rovers. Consider this cheap insurance if you have a flexible suspension.
Contact: Slickrock Fabrication