Lift off rattle

So, think I've bought a lemon....
1999 TD5 90.
It's got a rattle when I lift off on over run but only below 35mph, it's pretty loud and a bit worrying, seems to be coming from the rear but sound travels so can't be 100%.
It also happens when 1 wheel goes over a bump?
It's present in every gear and even with the clutch in.
So far I've checked rear prop shaft UJ's and alignment so the yolks are lined up straight, not 45 degrees.
Wheel bearings.
Front prop is brand new and set at 45 degrees on the yolks.
I've had the rear diff out (arb) reset the backlash and checked all bearing for play.
Slackened off the handbrake and checked the internals.
Checked for loose items underneath, exhaust, pipes brackets etc etc.
Transfer box works as it should but could that be the next thing to check? Any tricks for checking it? Doesn't appear to clonk or grind, spins quite freely without too much backlash between output flanges, I've had a bearing collapse in a TB before and it pretty much locked up the wheels.
Thanks in advance.

You say present in every gear and even with the clutch in. I read that as clutch disengaged. That's not what I'd call overrun really, but assuming that it starts as you lift off the throttle and keeps making the noise with the clutch pedal dipped, what happens if you go into transfer neutral or gearbox neutral?

Have you had a look at the radius arm bushes/axle ball joint etc..? What sort of rattle - tinny/hard etc..?

Thanks. Having had a decent spin tonight the ball joint and bushes is my next check. They seemed ok with a bar on them but I'll pull them all apart for a proper inspection tomorrow. I'm leaning towards the ball joint.

Check exhaust is touching chassis or is very near to chassis somewhere,can result in a loud rattle at times if it is.

Don't rule out front diff. If diff is the original type the rattle could be the shaft for the spider gears that has snapped.

LeftFoot said:

Don't rule out front diff. If diff is the original type the rattle could be the shaft for the spider gears that has snapped.

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The diff is an ARB and as mentioned I've had it out and inspected, reset the backlash as it was a bit out and checked all bearings.

Brake pads rattling in the calipers. Every 90 and 110 i have owned has had rattly pads in the calipers. Even genuine parts pads rattle in the calipers. My current old 90 does it to. A few months ago i was investigating what i thought was a loose hub bearing, turned out to be a pad moving in the caliper. Just the slightest amount of free movement and you can hear it especially with the window open.

alandrover said:

Brake pads rattling in the calipers. Every 90 and 110 i have owned has had rattly pads in the calipers. Even genuine parts pads rattle in the calipers. My current old 90 does it to. A few months ago i was investigating what i thought was a loose hub bearing, turned out to be a pad moving in the caliper. Just the slightest amount of free movement and you can hear it especially with the window open.

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I'll have a look but I think it's too loud for pads but you never know...

Willbof said:

The diff is an ARB and as mentioned I've had it out and inspected, reset the backlash as it was a bit out and checked all bearings.

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You said above that you had the "rear" out but you didn't mention the front. Hence the reason I said don't rule the front diff out.
I personally was chasing a loud metallic rattle for almost two years only to find out that the internals of my front diff were in pieces. One sure way to tell something is not right is to drain the oil and see what condition it is in.