Knocking sound at rear
Thread Starter
Instructor
Joined: Dec 2016
Posts: 190
Likes: 30
From: Wollongong Great Southern Land
Knocking sound at rear
72 SB has developed a knock that you can hear and feel when taking off in 1st or sometimes turning a sharp corner. Doesn’t happen all the time, if you ease the clutch out and take off slow it doesn’t appear. Sound appears to be coming from behind the seats, not from under the car if that makes sense. Changed the diff oil 6000klm ago. Thinking it might be the posi-trac diff or maybe something else? Tail shaft coupling?
Thread Starter
Instructor
Joined: Dec 2016
Posts: 190
Likes: 30
From: Wollongong Great Southern Land
Thanks Stormin,
checked the main and half shafts, all tight and no loose play. Wheel bearings not sloppy either. Looks like it may be a diff thing. One for the mechanic by the looks of it.
interesting when you put the boot it, there’s no slippage or lack of torque, performance wise it’s tight, just this clunk. Maybe the posi-traction part of the diff is wearing or needs a service/ rebuild
checked the main and half shafts, all tight and no loose play. Wheel bearings not sloppy either. Looks like it may be a diff thing. One for the mechanic by the looks of it.
interesting when you put the boot it, there’s no slippage or lack of torque, performance wise it’s tight, just this clunk. Maybe the posi-traction part of the diff is wearing or needs a service/ rebuild
Thread Starter
Instructor
Joined: Dec 2016
Posts: 190
Likes: 30
From: Wollongong Great Southern Land
Thanks Don,
had That replaced 2 years ago and was the first thing I checked when it was on the ramps. From memory the snubber in my case had similar issues but when changing gears. This happens in first on take off or when going around sharp corners, it’s appearing to be diff related. Won’t know for sure till the guys can look at it on the hoist, failing that take the diff apart
had That replaced 2 years ago and was the first thing I checked when it was on the ramps. From memory the snubber in my case had similar issues but when changing gears. This happens in first on take off or when going around sharp corners, it’s appearing to be diff related. Won’t know for sure till the guys can look at it on the hoist, failing that take the diff apart
