Loses drive then comes back

Hi all my 300tdi 94 es manual drives along then loses all gears. It is as if the transfer box is jumping into neutral. It shudders whilst doing this then if I push it into low n back into high it will drive again but I have to ride the cluch a little bit to pull off.
I know shes a old beast with nearly a quarter of million miles but I resurrected it from near death once n don't want to scrap it :'(
Regards Steve

Sounds like you're in diff lock to me.

It does it in diff lock or not I've tried it both ways

could the linkages be slipping. Take off the cover around the gear levers and have a look. If they've been wrongly set up having had change of gear box / transfer box. They might not be set up correctly.

smurphy said:

It does it in diff lock or not I've tried it both ways

Click to expand...

Is the diff lock light on?

I'll have a look tomorrow at the the linkage. The light comes on when selecting diff lock n goes out after a bit when it goes off.

Well its gone all together. No drive with or without diff lock, it does sound like something is spinning when I let the cluch out. I think the centre diff has gone or may the output shaft on the gearbox.

is it actually engaging hi/low ,grub screw inside lever housing on top of t/box can come loose , center diff can be checked by jacking one front wheel up , in diff lock it wont turn ,in gear t/box and g/box it wont turn ,if its clutch failure you shouldnt feel any difference in gear changes with engine running clutch pedal pressed or not ,mainshaft input gear wear can be seen by removing pto cover and clunking when setting off and gear changes would have been heard felt previous

I think its definitely engaging hi and low because if the T/box is in neutral there's no noise of such until I engage one or the other. The props aren't turning, so I don't think it's at the axles. I don't think it clutch because it would engage gears again an no slipping at all previous. I may just change them both if I can find one at the right price.
Regards Steve n thanks

worth dropping sump off t/box and looking , center diff failure isnt rare

Would I be able to see if I took it off?

Found the problem. Its the clutch, funny hey that it would engage and sometimes not.
Thanks guys again for your input