Hi Range, Lo Range, Diff Lock - Explain it to me please?
Discussion
Hi folks
On saturday I had 2 hours of off-road tuition in a Defender at nyoffroad.co.uk - very good I might add. Anyway, I've got the bug now and I think i'm going to get myself a cheap 4 x 4 and do some pay 'n' play days.
Now, the guy showed me around the defender we were in, put the car in diff lock and off we went, he did breifly explain what it all meant but I was fixated with driving so didn't take it all in. So, can some explain:-
On saturday I had 2 hours of off-road tuition in a Defender at nyoffroad.co.uk - very good I might add. Anyway, I've got the bug now and I think i'm going to get myself a cheap 4 x 4 and do some pay 'n' play days.
Now, the guy showed me around the defender we were in, put the car in diff lock and off we went, he did breifly explain what it all meant but I was fixated with driving so didn't take it all in. So, can some explain:-
- What all the different options on the transfer box mean and how they work
- How to test the transfer box when I go and look for a vehicle (i hope to take a Landy Expert when buying, but probably only after i've been and checked some out first)
http://www.rubicon-trail.com/4WD101/difference_4WD...
www.4x4abc.com
www.4x4abc.com
Edited by Hereward on Monday 22 March 17:28
normalbloke said:
jagracer said:
plasticpig said:
Only the Discovery has a Diff Lock as standard.
Which Discovery is that then?HTH
plasticpig said:
Only the Discovery has a Diff Lock as standard.
some did, some didn't, some could be retrofitted. Classic range rovers always had a centre diff lock (early 4spd manuals were vacuum operated, latter ones manual with the LT230), although some were auto locking (Borg warner chain box).
Defenders with an LT230 (can't think of any non LT230 transfer boxed defenders) all had centre diff locks.
Vehicles with switchable 4wd (ie on the road you only have drive to the rear wheels- some jeeps, early Series Landrovers, some jap stuff) don't have a centre diff lock as there is no need for a centre differential- any axle wind up is spun away in mud.
http://www.youtube.com/watch?v=yYAw79386WI
this is the best explanation for why a differential is needed- think of a centre diff as working the same as an axle diff- as you go around corners the speeds of all 4 wheels are different, this means that BOTH axles are rotating at different speeds- if you don't have a centre diff lock then you get transmission wind-up which will either cause the vehicle to seize up, or break a component.
The massive problem with a differential is that it inherently allows power to follow the path of least resistance- so you could have 3 wheels on tarmac and one in slurry mud, and technically all the power of the engine could be transferred though the centre diffs and the axle diffs to the one single wheel in the mud- hence you won't move. A centre diff forces power equally to both axles (we'll ignore LSD centre diffs), which means you have true 2wd drive- you are forcing drive to at least 2 wheels. This doesn't mean you will always move- in more serious situations (when crossaxled, in lots of mud, when beached etc) you will rev the engine and just get 2 wheel on each axle spinning uselessly- the wheel with drive doesn't get any power.
You can of course get axle lockers which, when engaged, give you either 2wd, 3wd (centre diff lock and a rear OR front axle lockers) or 4wd.
Cars with full 4wd include Ladncruiser 80 series, Merc G-Wagens, Unimogs, tractors, and a few more that i can't think of! No landrovers had axle lockers standard from the factory- you can get ARB air lockers for retrofit but you have to fix the rest of the drivetrain at the same time!
99.9% of people who drive 4x4s will never use axle lockers, so unless you get into expeditions (and its really not vital), competitions or serious pay and plays/greenlanes (and if you need axle lockers on a greenlane then you shouldn't be there) then its not a problem.
Axle lockers have one major problem- they can get you MORE stuck than you would otherwise have been as you get further into the bog!
to the OP, ive dont quite a few pay and play days at NY offroad when i had my '90 and my series 3! did he take you down 'pinball alley'? if he did you will most definately know what i mean! i went down in my series 3, was an exciting experience! and also did you notice if theyve fixed the seesaw yet? that was good fun before it fell apart.
taldo said:
to the OP, ive dont quite a few pay and play days at NY offroad when i had my '90 and my series 3! did he take you down 'pinball alley'? if he did you will most definately know what i mean! i went down in my series 3, was an exciting experience! and also did you notice if theyve fixed the seesaw yet? that was good fun before it fell apart.
See-saw was not in use, by me or the pay 'n player that was there (he was too busy rolling his military defender). Pinball alley was off-bounds due to how slippy it was, it had rained all night and was raining pretty hard for all of my driving, I didn't mind as that made the "fording" sections much more interesting.All in all a really good day and I have been trawling the classifieds for a cheap disco since!
pugwash4x4 said:
Cars with full 4wd include Ladncruiser 80 series, Merc G-Wagens, Unimogs, tractors, and a few more that i can't think of! No landrovers had axle lockers standard from the factory- you can get ARB air lockers for retrofit but you have to fix the rest of the drivetrain at the same time!
Didn't have to fix the rest the drivetrain on my 90 V8 which came with 4 pin diffs, 24 spline halfshafts and LT 85 gearbox from the factory when I fitted a true-trac up front and a detroit locker in the rear. Eight years later I still didn't have to fix it again. . . . . . 
OnTheOverrun said:
pugwash4x4 said:
Cars with full 4wd include Ladncruiser 80 series, Merc G-Wagens, Unimogs, tractors, and a few more that i can't think of! No landrovers had axle lockers standard from the factory- you can get ARB air lockers for retrofit but you have to fix the rest of the drivetrain at the same time!
Didn't have to fix the rest the drivetrain on my 90 V8 which came with 4 pin diffs, 24 spline halfshafts and LT 85 gearbox from the factory when I fitted a true-trac up front and a detroit locker in the rear. Eight years later I still didn't have to fix it again. . . . . . 1/10 for the non convincing Landrover in reliability shocker atatement!
normalbloke said:
OnTheOverrun said:
pugwash4x4 said:
Cars with full 4wd include Ladncruiser 80 series, Merc G-Wagens, Unimogs, tractors, and a few more that i can't think of! No landrovers had axle lockers standard from the factory- you can get ARB air lockers for retrofit but you have to fix the rest of the drivetrain at the same time!
Didn't have to fix the rest the drivetrain on my 90 V8 which came with 4 pin diffs, 24 spline halfshafts and LT 85 gearbox from the factory when I fitted a true-trac up front and a detroit locker in the rear. Eight years later I still didn't have to fix it again. . . . . . 1/10 for the non convincing Landrover in reliability shocker atatement!
to be fair though 4pin diffs, and 24 splines usually means AEU252s which were the strongest CVs that LR produced- so its not surprising really.
You have to admit that with a LR drivetrain you have to drive to the capabilities of the drivetrain- for examply you wouldn;t be standing on your nose, with lost of lock, in low range, and boot it out. you'd break the CVs easily. A locker only makes that more likely.
Something lik a G, Mog, or LC80 you can get away with that sort of abuse for years on end with no ill effect.
You have to admit that with a LR drivetrain you have to drive to the capabilities of the drivetrain- for examply you wouldn;t be standing on your nose, with lost of lock, in low range, and boot it out. you'd break the CVs easily. A locker only makes that more likely.
Something lik a G, Mog, or LC80 you can get away with that sort of abuse for years on end with no ill effect.
OnTheOverrun said:
normalbloke said:
OnTheOverrun said:
pugwash4x4 said:
Cars with full 4wd include Ladncruiser 80 series, Merc G-Wagens, Unimogs, tractors, and a few more that i can't think of! No landrovers had axle lockers standard from the factory- you can get ARB air lockers for retrofit but you have to fix the rest of the drivetrain at the same time!
Didn't have to fix the rest the drivetrain on my 90 V8 which came with 4 pin diffs, 24 spline halfshafts and LT 85 gearbox from the factory when I fitted a true-trac up front and a detroit locker in the rear. Eight years later I still didn't have to fix it again. . . . . . 1/10 for the non convincing Landrover in reliability shocker atatement!
Laning and overland expeditions are taxing enough. But maybe don't produce the same stresses as competition use. Trialling can and will break stuff. Especially Series Landy's. But I know of a lot of 90's with busted diffs and axles. Myself included, did a front axle the other year.
As for centre diff locks. Loads of vehicles have them, but most or many are more clever than the Land setup. Jeep offer a centre diff lock, but it has 3 positions:
-2wd only
-part time full 4 wheel drive, like a Defender with CDL open
-full time 4wd, like a Defender with the centre diff locked
http://www.youtube.com/watch?v=Z03d1HBNFvs
diagonally opposing wheels are lifted free from the ground- so the diffs spin all the power to those wheels.
its very common to see the effects of this in competitions and trials etc
diagonally opposing wheels are lifted free from the ground- so the diffs spin all the power to those wheels.
its very common to see the effects of this in competitions and trials etc
Basic rule of thumb for driving your Disco off road, low range, 3rd gear most of the time, including up hills, 1st gear for downhills, into centre difflock low, when there's a chance of wheels spinning. ie mud, or large steps, but get out of centre difflock as soon as problem cleared.
To change into low gear/difflock, you need to be moving, preferably forwards in a straight line (mine won't go in when going backwards) at walking pace or less.
The next things you need to be looking at if you intend to do any more, is diff guards (approx £18 each) decent recovery points at the front and rear of your Disco.
The towbar you've found is a plough, so that needs to come off, but you'll need something else very substantial, probably jate rings would be best for you (approx £15 each) Now look at the front end, the plastic valance under the bumper needs to be removed, or the next lane might just do it for you! then you need to decide what you are going to do for recovery points, the best bet would be changing the whole bumper for a specialist one with recovery points included, (prices vary from £100 2nd hand to £300+ new)
Buy a decent recovery strap at least 14 ton breaking strain (mine cost me about £16 I think!)
There's loads of other stuff that you can spend money on, but the above in my mind are the basics that will give you a fighting chance of enjoying your laneing without having lumps torn off your Disco that just aren't up to it, when you next get stuck. (and you will!)
To change into low gear/difflock, you need to be moving, preferably forwards in a straight line (mine won't go in when going backwards) at walking pace or less.
The next things you need to be looking at if you intend to do any more, is diff guards (approx £18 each) decent recovery points at the front and rear of your Disco.
The towbar you've found is a plough, so that needs to come off, but you'll need something else very substantial, probably jate rings would be best for you (approx £15 each) Now look at the front end, the plastic valance under the bumper needs to be removed, or the next lane might just do it for you! then you need to decide what you are going to do for recovery points, the best bet would be changing the whole bumper for a specialist one with recovery points included, (prices vary from £100 2nd hand to £300+ new)
Buy a decent recovery strap at least 14 ton breaking strain (mine cost me about £16 I think!)
There's loads of other stuff that you can spend money on, but the above in my mind are the basics that will give you a fighting chance of enjoying your laneing without having lumps torn off your Disco that just aren't up to it, when you next get stuck. (and you will!)
Gafferjim said:
Basic rule of thumb for driving your Disco off road, low range, 3rd gear most of the time, including up hills, 1st gear for downhills, into centre difflock low, when there's a chance of wheels spinning. ie mud, or large steps, but get out of centre difflock as soon as problem cleared.
To change into low gear/difflock, you need to be moving, preferably forwards in a straight line (mine won't go in when going backwards) at walking pace or less.
The next things you need to be looking at if you intend to do any more, is diff guards (approx £18 each)
Why would you want to get out of diff lock?To change into low gear/difflock, you need to be moving, preferably forwards in a straight line (mine won't go in when going backwards) at walking pace or less.
The next things you need to be looking at if you intend to do any more, is diff guards (approx £18 each)
Off road unless it isn't taxing at all then I'd say always use diff lock, but then I do more competition than lanes.
Also not sure how much benefit diff guards really are, if you play on large rocks a lot, ok. But I've never know anyone to actually break the outside of a diff.
Gafferjim said:
decent recovery points at the front and rear of your Disco.
The towbar you've found is a plough, so that needs to come off, but you'll need something else very substantial, probably jate rings would be best for you (approx £15 each) Now look at the front end, the plastic valance under the bumper needs to be removed, or the next lane might just do it for you! then you need to decide what you are going to do for recovery points, the best bet would be changing the whole bumper for a specialist one with recovery points included, (prices vary from £100 2nd hand to £300+ new)
Buy a decent recovery strap at least 14 ton breaking strain (mine cost me about £16 I think!)
There's loads of other stuff that you can spend money on, but the above in my mind are the basics that will give you a fighting chance of enjoying your laneing without having lumps torn off your Disco that just aren't up to it, when you next get stuck. (and you will!)
The towbar you've found is a plough, so that needs to come off, but you'll need something else very substantial, probably jate rings would be best for you (approx £15 each) Now look at the front end, the plastic valance under the bumper needs to be removed, or the next lane might just do it for you! then you need to decide what you are going to do for recovery points, the best bet would be changing the whole bumper for a specialist one with recovery points included, (prices vary from £100 2nd hand to £300+ new)
Buy a decent recovery strap at least 14 ton breaking strain (mine cost me about £16 I think!)
There's loads of other stuff that you can spend money on, but the above in my mind are the basics that will give you a fighting chance of enjoying your laneing without having lumps torn off your Disco that just aren't up to it, when you next get stuck. (and you will!)
pugwash4x4 said:
steering guard before diff guards- youare FAR more likely to bend your drag link and steering arm than destroy the front of your diff- even though that is entirely possible
yep agree, bent a few steering arms, but then again I've also bent my steering guard too 
Done a front diff in too, but that was more to being airborne
and no diff guard would have helped..Gassing Station | Off Road | Top of Page | What's New | My Stuff