diff lock problems

i think i may have a drive problem with my disco.
after doing a quick search i have found that if the disco drives with the diff lock on, then there is a possible problem with the halfshafts/cv joints, but the procedure for testing them seemed rather confusing......
from what i gather it is best to jack up each wheel and try to turn it with the diff lock OFF to see what happens, if the relevant prop doesn't move when i do this, then there is a problem with that side?

can any one clarify this in an easy to understand way please?

the main reason i ask is because if i move the diff lock lever to the right of the vehicle (normal hi/low range?) then i get no drive. will i be able to see the prop turning if i put it in gear and try this?

also there is a quite loud clunk from what sounds like the prop when taking up drive, although there is no play that i can detect in any of the joints....?

help please anyone, thank you..

It sounds like you've snapped an half shaft in one of the axles. disconnect front propshaft and try to drive it with the difflock engaged. if it moves then you've snapped an half shaft in the front axle. if it doesn't move then you've snapped one in the rear axle. this can be confirmed by reconnecting the front prop and disconnecting the rear and repeating the exercise.

What's probably happening is that with the difflock disengaged all the drive goes to the wheel with least rolling resistance. in this case the one with a broken shaft. If you disconnect drive to the broken axle and lock the centre diff then all the drive goes to unbroken axle.

cheers.
if i disengage the transfer box, put it into first and let the clutch out with the handbrake off, will the props turn as if driving? if so, then would that help to highlight which axle has the problem, as it would be simulating being stuck without the diff lock on?

No as if the transfer box is in neutral none of the prop shafts will turn. All the handbrake does is stop both the propshafts from turning you need to be able to engage difflock and drive the vehicle. easiest way is to remove a propshaft as explained in earlier post. There may be other ways to figure it out but that's the method I use and it is foolproof. try doing a search there's plenty of other people have had the same problem you've got.

If it will only drive in difflock then 99.9% of the the time it's a snapped half shaft

hmmm, with the diff lock OFF and the handbrake OFF, when i engage first and release the clutch, the front prop turns, but no drive.
when i jack each front wheel up in turn and spin the wheel neither front wheel turns the prop....and i can hear a crunching noise from the RH front side of the diff.

does this sound like the diff is u/s?
please say no......

sounds like a snapped half shaft to me

how do i determine which one it is though?
as neither wheel turns the prop when they are jacked up individually.

I think you've reached the point of pulling them out and having a look, RH one first if that is where the noise is!

quattro6999 said:

how do i determine which one it is though?
as neither wheel turns the prop when they are jacked up individually.

Click to expand...

That's right!

If you have snapped a half shaft in the front axle NEITHER of the front wheels when turned will turn the prop shaft because the DIFF will allow the turning of either wheel to end at the snapped shaft instead of being directed to the propshaft.

Believe the man who says to go for the noisy side prop shaft!

CharlesY

thank you one and all. time to break out the socket set, compressor and air wrench then.....it's time to get oily!!!