Diff lock query

[kevinr]

Hi,

I got my Landrover Discovery 1 in October last year, and so am fairly new to them.

I was under the impression that the car is permanent 4 wheel drive, and the diff lock, locked all 4 wheels for steep climbing/descending, however, I recently found that when I was trying to pull a caravan out of a muddy field, my rear wheels stayed put and my fronts spun..hence, I went nowhere, even though I had my diff in Low.

Could anyone please give me an idiot friendly explanation on how the diff on a Discovery works?

My landorver is a P reg, 3.9 V8 model if that helps.

Thanks in advance.

[lynall]

Perm 4 wheel drive only one whel has to spin and you lose all drive, lock centre diff and one wheel on each axle has to spin before you lose drive

Only way to lock all 4 wheels is to have locking diffs in the axles.

The centre diff is in the transfer box.

Lynall

[FridgeFreezer]

I hate to point this out but it's explained in your owner's manual If you ping me your e-mail address I can send you a short PDF guide to how 4x4 works from the Shire Land Rover Club newsletter.

You need diffs to go round corners, however if one wheel can spin freely all the power takes the path of least resistance and spins that wheel. Centre diff-lock is usually enough to keep you going. Axle difflocks are the only way to have true 4x4 (one wheel with grip and you'll still move) however for caravanning you're unlikely to need them Remember to disengage centre difflock once back on tarmac or you could damage your vehicle.

The biggest help (apart from engaging centre diff lock) in that situation are a decent set of tyres - All Terrains (AT's) such as BFGoodrich will give much better grip off-road whilst keeping excellent on-road characteristics, and a good set of Mud Terrains (MT's) will behave well enough on the road and give massively improved grip off-road. Again, BFG MT's are almost unbeatable as an all-round tyre, I know several people who run them as a road tyre and get tens of thousands of miles out of a set.

[thebiglad]

Hi,

I got my Landrover Discovery 1 in October last year, and so am fairly new to them.

I was under the impression that the car is permanent 4 wheel drive, and the diff lock, locked all 4 wheels for steep climbing/descending, however, I recently found that when I was trying to pull a caravan out of a muddy field, my rear wheels stayed put and my fronts spun..hence, I went nowhere, even though I had my diff in Low.

Could anyone please give me an idiot friendly explanation on how the diff on a Discovery works?

My landorver is a P reg, 3.9 V8 model if that helps.

Thanks in advance.

Hi Kevin, unfortunately "permanent four wheel drive" doesn't actually mean that all 4 wheels will drive all of the time. If it did, you would never be able to turn a corner !!

What Lynall says is correct in that if you are in a situation where traction is likely to be a problem, then you select Difflock and that apportions drive 50:50 between the front and rear axles. The big problem is the if you get 1 wheel on each axle slipping, then you don't go anywhere.

The only non-professional 4-wheel drive car I know of that had locking diffs on the axles as well as in the centre was the Mercedes G-wagon.

You will often come across 4x4's that have a Limited Slip Diff, usually on the back axle. Usually Japonese.

[dangerous doug]

if you diddnt have diagonal wheels spinning it is possible you have broken a diff or half shaft. what tyres you running?

[alfredenewman]

Hi Kevin, unfortunately "permanent four wheel drive" doesn't actually mean that all 4 wheels will drive all of the time. If it did, you would never be able to turn a corner !!

What Lynall says is correct in that if you are in a situation where traction is likely to be a problem, then you select Difflock and that apportions drive 50:50 between the front and rear axles. The big problem is the if you get 1 wheel on each axle slipping, then you don't go anywhere.

The only non-professional 4-wheel drive car I know of that had locking diffs on the axles as well as in the centre was the Mercedes G-wagon.

You will often come across 4x4's that have a Limited Slip Diff, usually on the back axle. Usually Japonese.

you havent looked at the 6 pot diesel land cruisers too closely have you not all but most have electric lockers on one or two axles

[FridgeFreezer]

The only non-professional 4-wheel drive car I know of that had locking diffs on the axles as well as in the centre was the Mercedes G-wagon.

Disco 3 anyone?

[kevinr]

thanks for all the replies, they have been helpful.

I'm not sure if it was diagonal wheels that were spinning, I was inside, and the other guy was outside on my side, so he wouldn't have seen if the other one was spinning, and since I didn't know how it worked, it never occured to ask.

The tyres I have on are Goodyear Eagle GT+4's, not sure if they are any good, it was what it came with.

[BogMonster]

Disco 3 anyone?

Not that non-professional