It's the new hit game show "What's about to break now?"

MTerry · Oct 9th, 2013, 19:54

Something is very, very wrong with the drivetrain in my 740. I think I've narrowed it down to the clutch area, but some opinions and advice would be helpful before I pull the transmission (again.) What I've got is a knocking/clattering sound coming from the transmission tunnel. It's obviously something spinning making contact with something else. The clutch is still working perfectly and all the gears engage the same as they always have. The noise matches wheel speed (not engine speed) and I can get rid of it by depressing the clutch, at which point it "winds down" and stops, although it comes back even in neutral if I let the pedal out. So, I was thinking either a bad throwout bearing or a broken clutch spring, is there anything else in the clutch it could be, or could it be the transmission coming apart (again)? I discounted the transmission (M47) because it's still shifting well and putting power to the wheels smoothly, and also because I believe that engaging the clutch wouldn't make a difference in the noise since it would be generated behind it if it were a transmission problem.

stephend · Oct 9th, 2013, 20:36

Broken gearbox mount, allowing the front of the propshaft to come into contact with the transmission hump...?

MTerry · Oct 9th, 2013, 20:50

Don't think so because I can still hear it when the car is stopped in neutral.

MTerry · Nov 14th, 2013, 19:53

ANSWER: The pilot bearing failed and the vibration at the forward end of the input shaft killed the bearing at the back. It's still making a horrible whining noise, but it's still working.

Oct 9th, 2013, 19:54	#1
MTerry Bored Member Last Online: Nov 23rd, 2020 19:46 Join Date: Oct 2006 Location: Baltimore, Maryland, USA	It's the new hit game show "What's about to break now?" Something is very, very wrong with the drivetrain in my 740. I think I've narrowed it down to the clutch area, but some opinions and advice would be helpful before I pull the transmission (again.) What I've got is a knocking/clattering sound coming from the transmission tunnel. It's obviously something spinning making contact with something else. The clutch is still working perfectly and all the gears engage the same as they always have. The noise matches wheel speed (not engine speed) and I can get rid of it by depressing the clutch, at which point it "winds down" and stops, although it comes back even in neutral if I let the pedal out. So, I was thinking either a bad throwout bearing or a broken clutch spring, is there anything else in the clutch it could be, or could it be the transmission coming apart (again)? I discounted the transmission (M47) because it's still shifting well and putting power to the wheels smoothly, and also because I believe that engaging the clutch wouldn't make a difference in the noise since it would be generated behind it if it were a transmission problem. __________________ Elphie - '98 V70 AWD, also Polar White Sophie - '09 XC90 V8, Shadow Blue Gloria - '93 244 in Ruby Red Metallic Sandy Blu - '07 C70, Celestial Blue

Oct 9th, 2013, 20:36	#2
stephend Premier Member Last Online: May 27th, 2024 22:10 Join Date: Dec 2007 Location: S. Wales View Photos By: stephend	Broken gearbox mount, allowing the front of the propshaft to come into contact with the transmission hump...? __________________ 1989 740 GL 2.0 estate 2000 V40 2.0 (gone) 2005 Toyota Avensis 2.0 estate (gone) 2012 Ford Mondeo 2.2 TDCi estate 1999 Land Rover Discovery 2 TD5

Oct 9th, 2013, 20:50	#3
MTerry Bored Member Last Online: Nov 23rd, 2020 19:46 Join Date: Oct 2006 Location: Baltimore, Maryland, USA	Don't think so because I can still hear it when the car is stopped in neutral. __________________ Elphie - '98 V70 AWD, also Polar White Sophie - '09 XC90 V8, Shadow Blue Gloria - '93 244 in Ruby Red Metallic Sandy Blu - '07 C70, Celestial Blue

Nov 14th, 2013, 19:53	#4
MTerry Bored Member Last Online: Nov 23rd, 2020 19:46 Join Date: Oct 2006 Location: Baltimore, Maryland, USA	ANSWER: The pilot bearing failed and the vibration at the forward end of the input shaft killed the bearing at the back. It's still making a horrible whining noise, but it's still working. __________________ Elphie - '98 V70 AWD, also Polar White Sophie - '09 XC90 V8, Shadow Blue Gloria - '93 244 in Ruby Red Metallic Sandy Blu - '07 C70, Celestial Blue

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