12 bolt LSD axle clunk?

[[JP]]

I guys, need a little help to put my mind at ease and check if this is normal or not.

Seeing as I’ve never driven any other truck other than mine I don’t know if what’s happening is normal or I should be worried.

So basically I had a 12 bolt open diff, that kind of went wrong and I managed to get another diff, 12 bolt was well, which I had a bit of a result with it as my axle rebuilder guy found...

the differential in it was actually an early clutch-type limited slip diff which I believe was made by Eaton for GM, the part no. is ED 30060.
It 'feels' like an open diff when turning by hand, and only grips when one wheel tries to turn without the other under load.

Does anyone know much about these?

I used Kendall Limited-Slip Gear Lubricant SAE 80W-90
I then added a bottle of friction modifier to the diff as been told it would quieten the diff down, but it has not made much difference.
When driving around town is kind of ok on the tight turns setting of road junctions, but after a long drive, I guess once the oil is warm, then the clunking is quite noticeable, anything with the wheels not dead straight and it will clunk.
It feels like the back end is skipping along, it happens when setting of junctions when turning, even if only a slight turn on the wheels.…I think the only time it won’t clonk is if I’m not accelerating, like going downhill and let it roll…

Is there a way to adjust an axle so it doesn’t clunk this much? Or is it normal and no problem?

Thanks
JP