Disco 1 R380 output shaft wear question

Hi all,

Ever since I got my D1 (300tdi, manual, '97) it jerks a lot when taking off or changing gears. I read a lot about it and what seemed most likely to me was that the splines on the output shaft must be worn.

This summer I bought a spare gearbox with input and output shafts looking great and this week I got down to trying to replace the old one. Right now I'm at the stage where the transfer case is almost out. I can see almost the whole output shaft and it doesn't look bad at all to me. I checked the play in the gearbox as well with this occasion, in all gears, and it also seems fine, or at least just as good as the replacement.

At this point I'm thinking of putting everything back together as it is really difficult for me to take these out or put them back in with the car on the gravel. Right now the TC is suspended with a strap from inside the car and supported on a trolley jack from underneath.

There is no exaggerated play in the diffs and almost between the diffs and the wheels. Only one wrong thing I noticed yesterday is that the rubber doughnut on the rear differential is knackered. Could that be the only problem?

Is there any chance the play could come from the flywheel? As far as I'm concerned all 300Tdi's came with a single mass flywheel, so I haven't thought of it until now.

Any ideas?

Should I drop the tc anyway just to check for wear on the splines inside it? I personally haven't heard of them wearing out without the shaft on the gearbox. I am reluctant to drop it just to look at it, as I don't have a gearbox jack or any mates to help.

P.S.: to minimise the jerking I have to be really careful with the throttle and clutch whilst driving. May seem obvious but just in case it's any clue.

Many thanks,
Matei

If splines on gearbox are good and those inside the intermediate gear are good [ you could have checked all by removing just the round cover on back of transfer box and pulling intermediate gear ] Just put it all back.
Another check, put in diff lock and by hand see if much movement in front rear props when turned in opposite directions, should only be a little.
Most likely the donut. A mate changed his recently as he had slop like you and it made a difference but was not much better. He then switched to Defender prop and flange with standard UJ, much better. If you stick with donut get an original LR one.