Hi all thanks for the advice.
So the everyone thinks its not the big ends but could be the cranck bearings?
Is it a engine out job to change the cranck bearings ? or is there a way i could check what is at fault?
If it's the main bearings that you are talking about, then you can normally only get centre ones off, sometimes the front one, but I have never been able to get a rear one off without the gearbox out or engine out. I have cheated on occasions where you can slip the top bearings out past the crankshaft and left the rear one.
But take the sump off and take off the big ends first, the bearings should be grey sort of lead colour, if you see them worn through to the brass then they are gone, mark the caps with a centre dot or summit to make sure you fit them correctly in order, 1,2,3,4 and so on stick the marks all at one side, left side so all go same way. you will probably see some groves down to the brass where the oil feed hole is where at some time it's taken in ****, but that's not a problem, it is if a large surface area is worn through.
I doubt its the mains they give more of a rumble, but if you are in there take a couple of caps off.
And the last thing as you are in there, lever the crank forwards and backwards and check the float, if it's exessive then the thrust bearings are gone, but you should be able to get them out. Triumphs were bad for it and eventually it became difficult to get a gear since the clutch would not disenguage, so I guess with the engine running get somebody to press the clutch and see if the crank moves forward them back when released.
Check your oil pressure first just in case you have issues there, low oil pressure could still be present even though the light goes out and best to be safe