940 Turbo knocking from drive

  • Thread starter Thread starter Tony Stanley
  • Start date Start date
T

Tony Stanley

My 940 estate seems to be giving out knocking sounds from the rear under
hard acceleration in 5th from 60-75 or so. It sounds like small bumps on
the road a few times a second or so, but is definately linked to
acceleration and doesn't occur at different revs on the same piece of smooth
road.

It does get a bit of a hammering, have I worn out the universal joint, or
the support bearing or something?

1995 940 SE 2.3 Turbo estate, 115,000 miles
 
I would first check clearance around the exhaust pipe and make sure all
rubber devices are in place.
 
Gunnar Eikman said:
I would first check clearance around the exhaust pipe and make sure all
rubber devices are in place.
Click to expand...

The exhaust doesn't go anywhere near the drive shaft at the rear, and is
well secured. I'm faily sure the noise is comming from the rear, and I
think I would know the difference, its just not that sort of noise.

Its getting worse now, or I am looking for it more. Full tilt in 1st now
feels very rough.
 
I did not mean that the exahaust hits the drive train, possibly the
underbody of the car.

If you do have a mechanical problem, there are several candidates:

The Hardy disk (rubber thing) at transmission rear end. I have read that
these get worn and cause vibrations, without loooking noticeably bad.
They are a bit expensive to replace "just-in-case". I never had one fail
myself.

The support bearing, or rather its rubber housing. Same thing. Never
happened to me. One bearing went bad, but it created noise, a whining
sound like circular saw or so.

U joints. When they get worn (or jammed) they cause vibration and make
noise, although in my limited experience at all loads. I had one jam,
causing vibrations at highway speed. Sound and vibration was pretty much
independent on load. Same when coasting or accelerating.


--
Gunnar

240 Turbo Wagon '84 200 K Miles
940 Wagon '92 150 K Miles
on Swedish roads
 
a bad u joint would be my guess...does the
spped of the knocking change w/the speed of the car?
 
Also check your engine and gearbox mounts.

Cheers, Peter.

: a bad u joint would be my guess...does the
: spped of the knocking change w/the speed of the car?
:
:
:
:
: > I did not mean that the exahaust hits the drive train, possibly the
: > underbody of the car.
: >
: > If you do have a mechanical problem, there are several candidates:
: >
: > The Hardy disk (rubber thing) at transmission rear end. I have read that
: > these get worn and cause vibrations, without loooking noticeably bad.
: > They are a bit expensive to replace "just-in-case". I never had one fail
: > myself.
: >
: > The support bearing, or rather its rubber housing. Same thing. Never
: > happened to me. One bearing went bad, but it created noise, a whining
: > sound like circular saw or so.
: >
: > U joints. When they get worn (or jammed) they cause vibration and make
: > noise, although in my limited experience at all loads. I had one jam,
: > causing vibrations at highway speed. Sound and vibration was pretty much
: > independent on load. Same when coasting or accelerating.
 
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