Landcruiser diesel clutch shudder

Just over a weekago I finished converting my HJ61 cruiser from auto to 5 speed manual. Yes, I actually was silly enough to do this myself in the garage at home, even assembly of the transfer case on the gearbox. (I had a shop assemble the gearbox for me, as I didn't have access to a bearing puller or press for the rear mainshaft bearing). I also fixed a lot of small faults/problems that I knew were there, which has turned an average cruiser into an exceptional one.

The only problem is that the clutch shudders, not so much when taking off in low gears, but more so when changing down from 4th to 3rd, and even at low speed, 35-40kph. it does shudder on the up shift 3rd to 4th, but only if the release of the clutch pedal is drawn out, as when trying to change smoothly.

I have checked engine mounts, and found one was slightly loose so tightened that, no change. Gearbox mount is ok, I checked to see if the drive shafts were binding or hydraulicing (too much grease in the slip joints, and no where for air to be release when moving in and out) not that.

I checked the net and found 80 and 100 series cruiser owners have had problem with clutch shudder, but it appears to be when the vehicle is cold, and is lower gears.

I discussed this with mate yesterday, and we were wondering if clutch shudder has become more prevalent since the exclusion of asbestos from friction material? Has anyone suffered from similar circumstances and/or can anyone shed some light on this matter?

regards,

Martin Bristow