Help needed!! Knocking noise from rear

[Muli]

I need a bit of help please from all you e30 guru's out there.

I have an 89 325i sport, a couple of months ago the car developed a knocking and vibratation when accelerating hard in 1st gear.

I did a search and put the issue down to a diff bush, so got the uprated one from trust Zimbimmer (thanks for the parts) so while I was there I thought i'd also do the top mounts (good job they were falling to bits)

So I take it for a test drive . . . and it's still there!!

The drive shafts where checked and they appear to be ok . . .

Does anyone have any ideas as to what it could be???

[smithy318i]

Loose diff bolts?
Loose Subframe bolts?

[gareth]

is it definately from the rear? if you feel it through your arse, it's likely to be related to the prop, either the rubber guibo coupling or the centre bearing.

if it's a knocking noise replated to wheelspin on a hard launch or over bad surfaces, it could be the rear subframe mounts

[ifty]

im suffering from the same problem to since having the centre bush on the propshaft replaced.vibration above 20mph and knocking sometimes when driving off or changing gears.
is it the same signs if the drive shafts have gone?

[gareth]

drive shafts themselves very rarely fail.
i'd check your guibo coupling first, i bet one of the old bolts has now broken

[SPADGE]

ifty i would also be checking that your prop has been put back together properly so that it is still balanced!

[ifty]

thanx guys hope Muli gets to sort out the problem with his car too

[Muli]

Thanks for the response on this, been a bit busy in work doing the overtime to try and pay for all the work on the car.

The diff bolts are ok as the diff had to come off when fitting the new bush, I have not had a chance to check the subframe bolts as of yet.

As I mentioned before I'm only getting the problem when accelerating hard in first, theres no knocks or vibration when accelerating in any other gear!!

and its the same on any surface that I do it on.

I'll get the guilbo changed on it and fingers crossed this will cure the problem ??? do you think the centre bush is worth changing while i'm there???

Thanks again for the help