Thread: Quick Centre Diff Lock question..

As for what speed you can be travelling when the CDL is engage, it doesn't matter, there will be no limit, all you really need is that the front and rear axles are travelling at the same speeds.

I've been known to slip it in and out at 100km/h

As for gravel road speeds, it all depends on the road surface, tyre type, tyre pressures, your skillset, run off, etc, etc.

The old 'drive to the conditions' comes to mind and use your common sense.

Interesting one this! Ok, first, the CDL... As everyone before has said, no problem engaging it when on the move on dirt when in a straight line. Just don't do it when going around corners or when you are stuck with the wheels spinning!! If you are traveling in a straight line, both axles are covering the same distance.... so the center (transfer box differential is rotating as one lump and the bevel gears within this diff are stationary). If you are turning in a circle, the front axle is traveling in a greater arc than the rear... This means that it it is going marginally faster than the rear axle... (The longer the wheelbase, the greater the speed difference between the two axles). At this point, the small bevel gears in the center differential are rotating within the housing (which is also rotating!). All very confusing, but this means that the two interlocking halves of the center diff lock are rotating at different speeds so must not be engaged... Hope that made sense and helped a bit!!

Re braking hard, yes you are right in thinking that all the wheels should be braking the same amount, BUT, they never really do.... As said before, when you stand on the anchor pedal, you get thrown forward and upward.. You can't see it, but so does the rear of your Land Rover.. (unless you are driving a series vehicle!!) Stand on the brake pedal hard enough, and there can be very little weight on the rear wheels... meaning they lock (becoming fairly ineffective..). This is made worse on dirt because the left wheel is usually on the looser gravel, so is also loosing traction.... if it does, and your rear wheels are locked, suddenly the only wheel with any grip and being of much use is the front right. When this happens, your rear end suddenly decides to overtake your front end in a clock wise direction!! All great fun if you are expecting it, but not so much if you are in a 130 with an overloaded roof in a foreign country. (Just ask my SWIMBO)!! Sooooooo, by having the center differential LOCKED, when you do plant your foot on the STOP pedal, you are lessening the chance of the rear wheels locking as they are directly locked/linked to the fronts, and if you do manage to press hard enough and get all four wheels locked, at least you are still traveling in a reasonably straight line!! Also, with the center diff locked, you WILL have to stall the engine to lock all four wheels, whereas with it unlocked, if you lock the rears and manage not to stall the engine, it will try and drive the fronts and keep going!

Turned out a bit longer than planned but hope it makes sense and helps!!!!