Series Land Rovers

Differential Offset

By C. Marin Faure

Question: Why the half shafts are not the same length....

Answer: Actually the design of the LR's axles is deliberate and very intelligent. Both differentials were deliberately offset to one side. In the case of the front differential it's offset because the engine sump forces the driveshaft to be over to the right. But instead of taking the cheap, dumb-ass route that almost everyone else did (and still does) and center the rear differential, LR cleverly offset the rear differential so it's in line with the front one. While this doesn't make any difference to 99.999 percent of 4wd owners and drivers, whose idea of 4wd country is a gravel driveway, to people who actually depend on a 4wd to get them over rugged terrain, having the differentials in line and offset enables the driver to line a higher obstacle like a rock, stump, etc. down the other side of the undercarriage and not hit anything.

LR also incorporated this design feature into the Range Rover. The so-called "classic" model, the original configuration, has the differentials offset to the same side as the Series. The "middle" model, the 1995-2000-something version that looks like a Ford Explorer, also has both differentials offset and in line although they are on the left side of the vehicle instead of the right side. To be honest I haven't looked under the current model to see what they did with the differentials but it probably doesn't matter since none of these vehicles will ever see so much as a traffic bump.

When I bought my Series III new in '73, it came with all sorts of cool things including the complete workshop repair manual and a couple of booklets on off-road driving techniques, one for deserts and stuff and the other for snow and ice. The reasoning behind offsetting and lining up both differentials was spelled out along with a short description of how to take advantage of it.

I have taken advantage of this offset differential design on both the SIII and our '91 Range Rover on a number of occasions over the years. The only other company I'm aware of that had the smarts to set the axles of their 4 x 4s up this way is Toyota with the Land Cruiser, at least on the old ones. They too, touted the advantages of this design. So it's not LR that has a poor axle design, it's everyone else.

Note, a 1/4" hardened steel rod will pass through the diff. to help bang out that broken stub axle piece.