on my way home from green laning yesterday, my disco lost all drive but when i engage diff lock it can be driven , does anybody have any clue whats wrong this is the 2nd time this happen to me in less than 2 weeks in two differant discos, is it the trtansfer box or is it the diffs

Diff, half shaft or CV joint.

When you get home, chock wheels, out of diff lock, run engine with it in gear and take a look underneath. The spinning prop shaft points to the broken axle

thanks for that pal will go and have a look at that now

how do i tell if its the front or if its the rear diff whats gone

just tryed the carput it in high gear and put it in first and the front prop spinning like hell but the back one just judders like its stuck, can you help me

Sounds like its all fooked!!

meanbean said:

just tryed the carput it in high gear and put it in first and the front prop spinning like hell but the back one just judders like its stuck, can you help me

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sounds like either front diff, one of the front CV joints or one of the front half shafts

meanbean said:

just tryed the carput it in high gear and put it in first and the front prop spinning like hell but the back one just judders like its stuck, can you help me

Click to expand...

So that means there's something at the front that's fecked ..

OK, so next step, if it were me ...

Make sure the vehicle can't move .. Start engine, leave running in gear on tickover then under and look at the front and rear UJ on the front prop and check both are turning and that diff input flange is also turning, it should be, but if it isn't it's likely the splines on the prop have gone, but this is unlikely.

Both UJ's and the diff input flange should turn, either way, engine off.

If they aren't turning then there's an issue with the prop itself, as above, unlikely but possible.

If they are turning then it's most likely a front half-shaft and most likely to be nearside (longest) that's gone .. though these can also twist a bit more before breaking! so it really could be either ... Get a manual for your particular model and check the hub disassembly instructions.

I'd take off the hub dust caps, loosen the five hub drive endcap bolts and see what happens .. it's possible that the splined stub-shaft to CV joint has lost it's spline or you could be really lucky and the splines on the endcap have worn, which is a common enough occurrence that there are hardened/improved end-caps made by various companies! ... Only further disassembly can really determine what's wrong.

Basically the prop drives the diff, then the diff drives each side half shafts, which then, via the CV joint, drive the stub axles via the endcap and thus turns the wheels .. so any part in the axle vould be broken making the diff send all it's power to the broken side, resulting in no drive unless centre diff-lock is on.