96 Disco won't drive without diff lock engaged

I have a 96 Disco and the truck won't drive without the diff lock engaged. The diff lock shift lever will move where it needs to in the ways it needs to, but the transmission will not actually engage (or the wheels won't turn). The diff lock light on the dash turns on when the shifter is on driver side, and turns off when the diff lever is on the right side of the gear box... as it should. The truck will drive in both H and L with the diff lock engaged but neither when it is not engaged.

I went through several posts, here on LZ, and no one seems to have the same issue. Most of the post I find refer to a stuck diff lever. My diff lever isn't stuck... the truck just won't shift out of diff lock, even though the diff lock indicator light goes out.

Thoughts?

MacKillop said:

I have a 96 Disco and the truck won't drive without the diff lock engaged. The diff lock shift lever will move where it needs to in the ways it needs to, but the transmission will not actually engage (or the wheels won't turn). The diff lock light on the dash turns on when the shifter is on driver side, and turns off when the diff lever is on the right side of the gear box... as it should. The truck will drive in both H and L with the diff lock engaged but neither when it is not engaged.

I went through several posts, here on LZ, and no one seems to have the same issue. Most of the post I find refer to a stuck diff lever. My diff lever isn't stuck... the truck just won't shift out of diff lock, even though the diff lock indicator light goes out.

Thoughts?

Click to expand...

Half shaft, axle diff or front cv joint.
Take it out of diff lock and taking great care have a look underneath while some one starts it up and puts in gear. One of the prop shafts will turn, this will tell you which end the problem is

The front prop spins, but not the rear. So its the rear end... is this something that I can fix myself?

MacKillop said:

The front prop spins, but not the rear. So its the rear end... is this something that I can fix myself?

Click to expand...

No if the front prop spins and the car doesn't go anywhere then it is the front end that is the problem.
I don't know if you can fix it, what are you mechanical skills like? Have you got any tools?

MacKillop said:

The front prop spins, but not the rear. So its the rear end... is this something that I can fix myself?

Click to expand...

Definitely a problem on the front axle. CV joint most likely followed by half shaft and differential. It is an easy fix if you can do some mechanics.

Is the rear axle not the standard drive axle in the case of the Disco? Is the right front wheel the drive tire in the case of disengaged operation?

MacKillop said:

Is the rear axle not the standard drive axle in the case of the Disco? Is the right front wheel the drive tire in the case of disengaged operation?

Click to expand...

the more questions you ask the less likely I think you will be able to fix it...
You need to do some searches to read up about how four wheel drive and diff lock work

... I ask questions to learn how to fix it. Can't just wing it. I think the best way for "junior members" to learn to to ask questions which "senior members" can possibly answer, if they so please. I have to learn somehow, right?

If someone knows roughly what's going on, but just needs a few details to clarify it - or a 2nd opinion on a diagnosis, then fair enough. But if you have almost no knowledge, then its going to be frustrating explaining the basics in sufficient detail. Also a bit of common sense on how things work, goes a long way to helping out the diagnosis. For example, knowing that a propshaft connects to the diff, which turns the axle, is a common sense thing. So the prop spinning but not the wheels turning.....should be a basic thing. Also, knowing that the Disco is permanent 4WD (if it wasn't, how do you select 4WD on it - you do realise its a 4WD????) is a fairly basic thing that 99% of owners would know.

This is as good as any place to start:

HowStuffWorks "How Four-Wheel Drive Works"

happy reading.

I am a new owner (1 week) and have never had these discussions with anyone before. The understanding that I had was that the Disco was a real-wheel drive system when in 2WD like a Jeep or Bronco. The diff lock would then lock the front and rear axles to spin at the same speed to improve traction on less-than-ideal surfaces. If thats not the case, well, sorry you have to teach me. I was interested in fixing it because I am interested in being hands on with the things I enjoy... (earlier I was not really trying to be a smart ass). So do I REALIZE its 4WD?

Yes it is permanent 4 wheel drive. There is a centre diff that allows the front and rear axles to rotate at different speeds. The difflock locks this diff, making both props, and hence both axles rotate at the same speed. You use this on wet, slippy mud or grass, or snow to give you better traction

To put it bluntly, with the diff-lock engaged, because you have a half-shaft/ CV joint failure, you are in 2 wheel drive. Try doing a search for Rave & dowload it, it's the official LR workshop manual. It's free, gives you an idea how to rectify your problem. Haynes costs.

Best of luck

airhook

busterbus has the best tips ever

to do your cv follow this
http://www.landyzone.co.uk/lz/f41/cv-joint-renewal-68945.html

you need to follow this to take a diff out anyway

it probly wont be a cv joint m8 as thay tend to fly to bits and jam your sterring aswel (somthing you may notice)
it cud be a half shaft or a sheard drive member
but its more then likely your front dif
eather way its a bit of a buger to change

but what people on here has forgot to tel you which is very very important is
do not drive it
as if its a dif the broken bits wil fall out and get jamed in your crown wheel and lock up you front axle with no warning at all this cud be a bit of a problem
or if its a cv joint your stering cud lokup at any time
i know cos its hapend to me
so id get sombody to look at it who defo knows wot there doing m8 befor even taking it to the garage
its posable to drive if you find out for shure its the dif by removeing the front prop and removeing the front drive members therfore disconecting the dif
oil wil pis out but least you can get it some where so you can repair it