Stock Land Rover Comparisons


zhangh@cs.unc.edu


This page documents some of the key design differences between between Land Rover Discovery and Discovery Series II. The Disco II is a thoroughly redesigned vehicle; the changes are too many to enumerate. But I'll focus on important differences that affect off-road performance.
 
 
 
Discovery
Discovery Series II

The steering stabilizer sits low behind the front axle as part of the drag link, making itself an easy target for rocks. The lower image shows a slightly bent stabilizer. Images courtesy of Ho Chung, enhanced. (Note: this vehicle is far from stock, although the steering mechanism is. Don't panic if your Disco doesn't look like this :-) 


The Disco II stabilizer is "Defender style", sitting high near the Panhard rod. The rod behind the axle is a plain tube. While not as low-hanging as the DI stabilizer, the link still feels vulnerable. An RX "pre-bent" link would help. A Southdown-style skid plate should put the issue to rest once and for all.

The original Discovery employs a locking center diff with a shifter of five positions (4H, 4L, 4H lock, 4L lock, neutral). Photo courtesy of Ho Chung.

Disco II adopts the ETC (electronic traction control) technology and the lock on the center diff is no longer available. The transfer case shifter is simplified to 3 positions (H, L, and N) instead of 5. What's curious is that the diff can still be locked, but it's "for service purposes only" (right, we all go off-road for service). There is a warning light on the dash which turns on when the diff is locked. So, there is still a locking diff underneath, just minus the shifting mechanism. (p.s. Some lr-discovery list members have posted that they've been told by the dealer that the center diff lock IS still there. The lock can be engaged with a wrench from under the transfer case. This helps you to limp home in 2WD when a halfshaft is broken.)

The Discovery uses an A-frame rear suspension similar to the orginal range rover (and the new Grand Cherokee WJ - see picture). Photo courtesy of Ho Chung.

Disco II replaces the A-arm with a Watts linkage for better lateral control of the axle. This contributes to better handling on the highway. Also, Disco II posts better wheel travel numbers than the original Discovery.


Front shaft, axle side

Front shaft, T-case side

The original discovery uses the following joints:

  • Front shaft, axle side: U-joint; harmonic damper
  • Front shaft, T-case side: U-joint
  • Rear shaft, axle side: "Rotoflex" (pre-97 models); U-joint (98-99)
  • Rear shaft, T-case side: U-joint
Since both ends of the front shaft are standard U-joints, a large harmonic damper (the wheel-like thing) is install on the front diff carrier (see bottom of the first picture) to control vibration. For the rear, the rotoflex must have been regarded as offering enough vibration reduction, so no damper is installed. Rotoflex has a limited life span; 98 and later Disco's replace Rotoflex with a U-joint. Photo courtesy of Ho Chung.

Rear shaft, T-case side

Rear shaft, axle side

The Discovery Series II uses the following joints:

  • Front shaft, axle side: U-joint
  • Front shaft, T-case side: CV joint (doulbe-U-joint type
  • Rear shaft, axle side: "Rotoflex"; harmonic damper
  • Rear shaft, T-case side: U-joint
Disco II uses a CV joint on the transfer case side on the front driver shaft (like the Wrangler TJ), and thus elliminating the need for a front harmonic damper. A harmonic damper (of smaller size than the Disco I front damper) is installed on the rear axle to further (in addition to the rotoflex) reduce the vibration.

Disco II gets Range Rover axles.