Weird Noises...Gearbox??

Michael Donovan · Post by **Michael Donovan** » Sun Jun 29, 2003 1:46 pm

Last year I got a new clutch put in my car by a company in south auckland. A
couple of months later it began making strange noises everytime I went to
use the clutch..it sounded like the thrust bearing was shot to me. The
upshot was that I couldn't prove the company did not fit a new release
bearing so I ended up replacing the clutch again myself.
I didn't replace the pilot bearing in the flywheel.
Now sometimes I hear this new rattling type noise. It happens often when I
am decelerating with the car in gear but foot off the throtle.But it always
ceases if I put the car into neutral while decelerating. Does anyone have
any ideas...does it sound like a pilot bearing problem?

Any ideas appreciated.
Mike

SLYDIT · Post by **SLYDIT** » Sun Jun 29, 2003 2:31 pm

Its very common to have a squeaky clutch, If you
grease the slave cylinder to clutch fork pivot point
it will go away.When i had my clutch replaced i had
all new bearings and the noise was worse!!.If its more
of a rattling noise it would be wise to check the gearbox input shaft bearing.
The rattling on deceleration is most probably one of
the exhaust heat shields rattling, this is also very
common. The heatshield before the Cat converter seems
to be the most problematic, ensure that its crimped
tight and that its still clamped to the exhaust
correctly.Also the core of the cat convertor has been
known to come loose inside its casing and rattle
intermittantly.
Glenn "SLYDIT"
[...]

Michael Donovan · Post by **Michael Donovan** » Sun Jun 29, 2003 5:54 pm

Thanks Glen I'll check the heatshields etc.

Mike

Michael Donovan · Post by **Michael Donovan** » Sun Jun 29, 2003 6:51 pm

Thanks again Glenn...just to show I can spell!
I'll look at the heatshields etc first and cross my fingers it's not the
input shaft bearing...
Thanks again
Mike

Post by **simple** » Sun Jun 29, 2003 8:09 pm

I also had strange noises associated apparently with the clutch - now
gone since clutch replacement...

When I bought my car, 3.5yrs ago, I was told it had had a new clutch
put in shortly beforehand (which seems to have been true). About
1.5yrs ago I noticed a grinding (for want of a better word) noise on
over-run - ie. decelerating, in gear, with the engine doing the
braking. Under no other circumstance could I get the noise, and it
was only apparent in low gears. It sounded to me like it was coming
from the back & I wondered if it was the diff.

I changed the diff oil & checked everything I could - it made no
difference & the people I asked had no useful suggestions other than
wait & see if it gets worse. Eventually, it got sufficiently
annoying that I specifically avoided over-run (which I guess is a
reasonable idea anyway, in casual driving at least).

Recently I started getting horrendous squeals when gear-changing
(only while the clutch pedal was depressed) or slipping the clutch
while backing. It turned out to be the pilot bearing - it had
virtually seized - I got a new clutch kit installed & all is happy.
Thankfully, the grinding noise has disappeared too.

Apparently, the springs which are arranged/aligned in a circle around
the clutch were loose (four of them, I think, and I assume they're
absorbing some of the shock of clutch engagement). I wonder if the
'grinding' noise was these springs vibrating?

(I have no trouble believing that my perception of it "coming from
the back" was completely wrong - I also wonder if the noise was being
transmitted & radiated via the driveshaft. In any case, my car
doesn't make the noise any more & I can have whatever crackpot
theories I like

(I had the new clutch installed at Rotary Power, on the North Shore,
Auckland - they did a fine job)

Karl.

===============
On 29 Jun 2003 at 13:46, Michael Donovan wrote:
[...]

lou Girardin · Post by **lou Girardin** » Mon Jun 30, 2003 8:05 am

Does it stop if you disengage the clutch?

lou Girardin · Post by **lou Girardin** » Mon Jun 30, 2003 8:08 am

Although it's probably not the problem at hand, light forged -steel flywheels
can often produce a metallic grinding noise on overrun, it's because of the
different damping qualities of steel over cast iron. Mine drove me nuts till I
heard of the problem.

Michael Donovan · Post by **Michael Donovan** » Mon Jun 30, 2003 7:34 pm

Hi Lou
I'm not too sure what happens when I disengage the clutch..I'll check
tommorow.
I thinkthe noise lessons but maybe thats just because usually if I disengage
the clutch I take my foot off the throtle as well which will drop the engine
revs??

As far as I know the car has its original flywheel...it never made these
noises until the clutch was done.

Thanks for the tips.
Mike

lou Girardin · Post by **lou Girardin** » Tue Jul 01, 2003 7:59 am

Try the suggestion of lubeing the end of the clutch push rod where it bears on
the throwout arm.

MC · Post by MC » Tue Jul 01, 2003 8:53 am

Hi
could also try some CRC around the pivot for the clutch pedal inside the car
MC

Michael Donovan · Post by **Michael Donovan** » Tue Jul 01, 2003 7:00 pm

Today tried disengaging the clutch when the noise starts and it dissapears
every time, though revs drop off too. Weather permitting I'll try to lube up
the pushrod and MC's suggestion of the crc on the clutch pedal pivot.I reckon
it is coming from underneath the car though.
Thanks for the suggestions so far.
Mike

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