Outer Limits 4x4 Board

Hi there, I have a 96 D1 35" mudies true tracks front and rear etc etc, the problem i am having is that when i am flexed with wheels loaded up in rock climbing aplications, some times i am having trouble getting positive drive to the front wheels. If i power up normally i will get wheel spin to one wheel, i would combat this by adding little brake pedal to activate the true tracks and should create positive drive to both wheels but am finding when heavily loaded that something is slipping in the drive train. I am getting some creaking nosies (much like the sound of creeping a vehicle forward while on the brakes) but no positive drive to the front at all but getting positive drive to both rear wheels. if i pump the brakes while powering up i can jerk intermittent positive drive to both front wheels but this is not right. Whats going on, where can there be slippage in the drive train, i have been told that there can be no slippage in the true tracks, that they work or they don't it's one or the other, i have lifted the vehicle and tested both diffs/true tracks and thet seem fine, i also seem to be able to do a positive 4 wheel burn out in the dirt. Any ideas out there.
Be much appreciated, cheers.

Is it an auto?

G'Day, I don't know much about Disco's but it sounds like a centre diff issue. How do you engage the centre diff in yours?

They're normal LT230's.

True tracks are limited slip. not 100% positive lockers, what did you expect?

sound to me like you have not engaged the centre diff lock, it goes left to right aswell as forward and back... also auto lockers in the front of constant 4wd vehicles is not the best idea.

yes it is an auto, but i am getting drive to the rear and no drive to the front in extreme circumstances.
it's an LT230 so no viscous, (i beleive)
although it is a limo, i beleive i should get positive drive to at least one wheel, also the true tracks apparently operate on a worm gear drive system, not a plate system where you can get slippage, apparently they work or they do not, there is no in between.
What do you think???

There is an inbetween, which is why they're called torque biasing.

The TT will send a % of torque generated by the spinning wheel through to the wheel with traction. I don't recall the ratio.

Slunnie wrote:There is an inbetween, which is why they're called torque biasing.

The TT will send a % of torque generated by the spinning wheel through to the wheel with traction. I don't recall the ratio.

Hi Slunnie, cheers for your input and everyone elses too, so you saying maybe nothing wrong, maybe normal???

kitacooch wrote:

Slunnie wrote:There is an inbetween, which is why they're called torque biasing.

The TT will send a % of torque generated by the spinning wheel through to the wheel with traction. I don't recall the ratio.

Hi Slunnie, cheers for your input and everyone elses too, so you saying maybe nothing wrong, maybe normal???

If ONE front wheel si going around at all times, nothing is wrong, you have limited slip diff....torque biasing.....what ever the fark, they ain;t locking centres

If the front tailshaft ain;t going around, the centre diff isn't locking

cloughy wrote:

kitacooch wrote:

Slunnie wrote:There is an inbetween, which is why they're called torque biasing.

The TT will send a % of torque generated by the spinning wheel through to the wheel with traction. I don't recall the ratio.

Hi Slunnie, cheers for your input and everyone elses too, so you saying maybe nothing wrong, maybe normal???

If ONE front wheel si going around at all times, nothing is wrong, you have limited slip diff....torque biasing.....what ever the fark, they ain;t locking centres

If the front tailshaft ain;t going around, the centre diff isn't locking

x2

OK,, then i am going to assume the centre diff is not locking properly as there are times the rears are spinning but neither fronts are. So if centre diff is not locking, then what could be the problem???
I would event think that the centre diff may be locking but not remaining loocked, or is slipping, is this possible??? as i do not know or understand how the centre diff lock works..

kitacooch wrote:OK,, then i am going to assume the centre diff is not locking properly as there are times the rears are spinning but neither fronts are. So if centre diff is not locking, then what could be the problem???
I would event think that the centre diff may be locking but not remaining loocked, or is slipping, is this possible??? as i do not know or understand how the centre diff lock works..

The centre diff lock can give problems. I have known them not to be locked even though the diff lock light was on.

When the H/L lever is pushed across to the diff lock position, the linkage turns a lever above the front drive extension housing. In turn this pushes against a spring, and you rely on the spring force to move the shift fork to lock the diff.

As the mechanism moves along it hits the plunger of the switch for the diff lock lamp. If the switch is adjusted a whisker too low, or the plunger is sticky, it will prevent the diff from locking.

I'm afraid the news in not good for you! The 230 transfer when unlocked drives all power to the diff carrier. Diff is 4 pinnion and two side gears so drive is distributed through pinnions to side gears and tailshafts......When locked the front output shaft is connected to diff carrier via a dog gear. Rear is still driven through side gears.....What is sounds like is you have stripped the inner teeth off the dog gear. They are not very large and it does happen, lots of low range work and not unlocking when turning leads to much increased wear and eventual failure. Hope this helps.

Thanks guys, i will try to find out if my front tail shaft is spinning next time i face this problem and from there should be able to determine what is going on. I'm off to Rover for a week over New Years so am guessing i will have a result soon enough.
Thanks again and everyone have a Safe and Merry Christmas.
Cheers

Could be as simple as the switch for the light is not adjusted properly.
As said earlier " If a whisker out then stops it locking"