Grinding when in gear Left Rear
07-24-2011, 04:17 AM
#1
5th Gear
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Grinding when in gear Left Rear
Hi folks - looking for some guidance if possible.
1974 911S Targa.
When in 1st/2nd and going slow I'm getting a grinding metal on metal type sound from the left rear wheel, noise goes away when out of gear and can't be heard at speed in 3rd/4th/5th.
Worse when cold and once warmed up seems to go away.
The transmission g15 has been overhauled and still shifts fine like it always has - no judder in the clutch either.
I thought maybe wheel bearing? But if that were the case I'd expect it to carry on regardless of the clutch being engaged or not...
Possible a stuck piston in the caliper? But again dis-engaging the clutch wouldn't make this go away or so I thought/think.
Have had the wheel off and there is a slight grind from the caliper when turning - brake pads seem ok - no scouring on discs but maybe they're on the way out?
Wheel itself doesn't seem to have an over large amount of play in it either.
Suggestions much appreciated.
There also seems to be some rub marks on the shock in that quarter - it's a near new shock... but odd to see abrasion marks on the shock cylinder.
Again though why would dis-engaging the clutch cause the noise to go away?
Sorry I'm no mechanical whiz kid so bit in the dark here....
1974 911S Targa.
When in 1st/2nd and going slow I'm getting a grinding metal on metal type sound from the left rear wheel, noise goes away when out of gear and can't be heard at speed in 3rd/4th/5th.
Worse when cold and once warmed up seems to go away.
The transmission g15 has been overhauled and still shifts fine like it always has - no judder in the clutch either.
I thought maybe wheel bearing? But if that were the case I'd expect it to carry on regardless of the clutch being engaged or not...
Possible a stuck piston in the caliper? But again dis-engaging the clutch wouldn't make this go away or so I thought/think.
Have had the wheel off and there is a slight grind from the caliper when turning - brake pads seem ok - no scouring on discs but maybe they're on the way out?
Wheel itself doesn't seem to have an over large amount of play in it either.
Suggestions much appreciated.
There also seems to be some rub marks on the shock in that quarter - it's a near new shock... but odd to see abrasion marks on the shock cylinder.
Again though why would dis-engaging the clutch cause the noise to go away?
Sorry I'm no mechanical whiz kid so bit in the dark here....
07-24-2011, 04:31 AM
#2
RL Technical Advisor
Time for a little detective work here,....
Put the rear of the car on secure jackstands so the rear wheels are well clear of the ground. This allows you to start the engine and put the transmission in gear and let it idle.
Using a mechanic's stethoscope or a long-handled screwdriver as one, place the tip against various parts of the car with the engine idling in 1st gear. Listen at the wheel hubs, brake calipers, and various points all over the transmission, etc.
You should be able to isolate the noise using these techniques.
Put the rear of the car on secure jackstands so the rear wheels are well clear of the ground. This allows you to start the engine and put the transmission in gear and let it idle.
Using a mechanic's stethoscope or a long-handled screwdriver as one, place the tip against various parts of the car with the engine idling in 1st gear. Listen at the wheel hubs, brake calipers, and various points all over the transmission, etc.
You should be able to isolate the noise using these techniques.