New clutch rattling on 745 DT after 3000 miles

[viktor weisshaeupl]

745 Turbodiesel 1989 with 4 gears manually + overdrive. Since my old clutch
was rusted and did not disengage any more completely causing problems
putting in first gear, I bought a new Sachs clutch set and had it put in by
a little repair shop, done by a mechanic with longstanding Volvo experience.
It worked smoothly in the beginning but started to rattle after about 3000
miles when engaging the clutch with low revs in first gear. When engaging
the clutch in first gear with higher engine rpms the rattling is much less.
When engaging during shifting from 1-2 etc without accelerating there is no
rattling. When shifting and engaging with simultaneously accelerating, the
clutch rattle appears at higher frequency and for a very short period until
complete engagement has taken place.

I asked the mechanic, he suggested I should try to hold the clutch sliding
for a while driving uphill, I have not really done that yet. He thought that
changing the clutch and getting a new under warranty would be the only way
to solve the problem.

I have thought about softened engine suspension parts, they seem ok when
looking and feeling at them. As much as I could see from the Haynes repair
manual, there is no extra suspension for the gear box.

Any idea? What is the theory of clutch-rattling. Uneven surfaces and
resonance of engine suspension? Too high friction between surfaces?

Viktor Weisshäupl, Vienna, Austria
[email protected] in case of personal e-mail

 

[Peter Milnes]

If it only happens since the clutch was replaced it points to the new clutch
either being faulty or being assembled incorrectly. Did the clutch release
bearing get changed at the same time? Has the spring clip on the clutch
operating arm become deformed/detached? Could be that the "fingers" that operate
the clutch when release bearing presses on them have come out of adjustment.
Most likely your mechanic is right about the solution though.

Cheers, Peter.

: 745 Turbodiesel 1989 with 4 gears manually + overdrive. Since my old clutch
: was rusted and did not disengage any more completely causing problems
: putting in first gear, I bought a new Sachs clutch set and had it put in by
: a little repair shop, done by a mechanic with longstanding Volvo experience.
: It worked smoothly in the beginning but started to rattle after about 3000
: miles when engaging the clutch with low revs in first gear. When engaging
: the clutch in first gear with higher engine rpms the rattling is much less.
: When engaging during shifting from 1-2 etc without accelerating there is no
: rattling. When shifting and engaging with simultaneously accelerating, the
: clutch rattle appears at higher frequency and for a very short period until
: complete engagement has taken place.
:
: I asked the mechanic, he suggested I should try to hold the clutch sliding
: for a while driving uphill, I have not really done that yet. He thought that
: changing the clutch and getting a new under warranty would be the only way
: to solve the problem.
:
: I have thought about softened engine suspension parts, they seem ok when
: looking and feeling at them. As much as I could see from the Haynes repair
: manual, there is no extra suspension for the gear box.
:
: Any idea? What is the theory of clutch-rattling. Uneven surfaces and
: resonance of engine suspension? Too high friction between surfaces?
:
: Viktor Weisshäupl, Vienna, Austria
: [email protected] in case of personal e-mail
:
:
:
:
:
:
:

 

[Viktor Weisshaeupl]

If it only happens since the clutch was replaced it points to the new clutch
either being faulty or being assembled incorrectly. Did the clutch release
bearing get changed at the same time?

Yes, the whole set contained a new bearing

Has the spring clip on the clutch
operating arm become deformed/detached?
??

Could be that the "fingers" that operate
the clutch when release bearing presses on them have come out of

adjustment.

??

Could that be seen through the window in the clutch case which is covered by
a rubber part?

Viktor