Problem within drivetrain - slops when under acceleration

[Senna.In.The.Wet]

i

VX Commodore V6 Ecotec 210,000 Kms

Lately this problem has been getting worse...

If I am cruising down the freeyway at approx 90kmh, then i lift off the accelerator to back off... then put my foot back on the accelerator to pick up speed again, the rear end of the car will hesitate with a slight shudder that comes in a burst of 1, 2 or 3 slops with the space of 1 second. It only seems to happen when the is a transfer of moderate load onto the drivetrain - so when accelerating - and once the load is transfered and its slopped a few times, its then fine just cruising along.

The shudder consists of either 1, 2 or 3 slops that is coming from somewhere on the drivetrain I'm sure. the slops aren't really that loud (its like a low muffled thud) and causes the car to hesitate with each slop as you plant your foot.

This started about a couple of months ago, but back then was only like 1 slop when acellerating moderately anywhere from 80-100kmh. Now its about 3 slops (in 1 second)

However lateley, I'm noticing the slop slightly when accelerating from slow speeds (around 50ish kmh) and just this morning experienced another hestation from somewhere in the drivetrain when taking off from a stand still (previously this only started occurring at higher speeds).

Now Im not mechanical at all, but to me it feels like the diff is about to let go.. but not sure if its the diff or the universal / pinion / crown wheel... or even something to do with the tranny...

Anybody else experienced this before... its making me nervous when accelerating in the car now.

Any help is muchly appreciated.

[Adds_05]

i seem to have this problem in my vy also,interested to know what it could be

[Senna.In.The.Wet]

How long has yours been doing it for Adds?

[nick_]

Have you even jacked up the car and had a sticky beak underneath? It could be any number of possible problems..

[accentstencil]

Are you sure it's not a miss because sometimes a miss can feel like something is going on with the transmission or diff.

[graham7773]

jack the rear of your car up, place on stands. block the front wheels both sides of each wheel. put your transmission in neutral leaving the handbrake on. get under the car with a large screwdriver. put the screwdriver in the rear universal yoke and twist slowly back and forward with a bit of effort. You will see any movement in unis, cvs and backlash in the diff. good hunting

[Adds_05]

How long has yours been doing it for Adds?

ages now,im thinking it is a slight miss,will probably replace leads and see how i go

[showbags]

clean the plugs on the knock sensors