2.8 1992 GR y60 - Weird noise coming from bell housing/front of gearbox

[Blacksails]

Hey guys,

2.8 1992 Y60 patrol in Iceland on 40” tyres. Reads 275,000km on a broken Odo.

I have a strange knocking/rattling noise coming from the bell housing/front of the gearbox when the car is warm after being driven a bit.
The noise is only there when the clutch is engaged, if the clutch is disengaged (pedal pressed) then the sound disappears. If the car is sat in neutral with the clutch engaged after being driven for a bit it’s a rhythmic knocking that sounds rotational that kind of fades in and out in consistent intervals. If the car is cold I can’t hear it in the cab. I also have a slight grinding noise right towards the end of releasing the clutch pedal when pulling away in first, this is also only when the car is warm after being driven a good few KM’s, although I’m not sure if this is just rollover? Sometimes I can hear the knocking that I can hear neutral in the first few gears whilst driving but at some point road noise is too much and I can’t tell any more.

The knocking noise that I’m talking about is at its absolute worst in reverse. Reversing is silent until the very last bit of the clutch is released then it’s a very loud consistent knock, knock, knock,knock,

Shifting is fairly smooth, as is down shifting, except for if I try to move into first whilst coming to a stop. I usually have to wait until the car has stopped or is going very slowly to get back into first. First Patrol so I’m unsure what’s normal.

What does this sound like to you guys?? Input/output shaft bearings?

Video links so you can hear:

Right under gearbox/bellhousing (sounds like a small rock rattling around in there): https://youtu.be/LFaC7ZRLcS8?si=FYdSNjuZx2hGNACv

Outside vehicle: https://youtube.com/shorts/HlTiqm8Dj...R1OP_f_1FiFeVL

Reversing: https://youtube.com/shorts/F4EacZyhM...TPGlvZiVzvImkx

[mudnut]

Maybe a worn thrust bearing? Or something loose. Does the clutch fork fully disengage?

[Blacksails]

Clutch fork fully disengages, Yep. I was sitting in it today and it got quite loud. I found if idling in neutral I could gently push the gear stick towards 1st or 2nd (without engaging, just gently pushing towards) and the sound went away. Is this just backlash and rollover from an aging box? Don’t know if I should be worrying or not

[BrazilianY60]

If pushing the lever silents the rattle, it's definitely inside the box and not clutch or clutch fork related.
I would open it to fix it instead of leaving it for later. The noise makes me feel the coupling sleeve is loose or with excess play and thus bouncing back and forth.