Rear differential bushing play/movement

[Sven]

The car makes a slapping sound that is coming from the rear end when driving over bumps, or even the small turtles in the center of the road. We have looked everywhere for loose components and removed everything from the trunk. We are wondering if the problem could be excessive movement of the rear diff. carrier bushing (which is new). From the photos below you can see the 5mm of drop when the diff is hanging. With a jack I can push the gap closed. We took the bushing out and all seems ok. I can even move it a bit with my fingers. It seems this should be stiffer. Is this a normal amount of movement? The slapping sound could well be the rubber ridge hitting the silver metal lower plate.

thoughts?

 

[sfdon]

Stick a rag in the gap and try again.

 

[Peter Coomaraswamy]

Sven, others would know better, but I thought that there should not be any play in the space you picture. The piece is "formed" with rubber so it should have the same "connection quality" as a motor mount.

 

[30csl]

I am pretty sure that this is a faulty part also - when i jack cars up on the diff there is some movement as you would expect as that is the job of the bush but nothing like this.

 

[Stefan]

Hi Sven!
Perhaps a long shot, but is it the correct length on the bolt and the threads?
I notice additional washers in the pics, or?

 

[Sven]

It is not the bolt. I originally thought that the bolt might be loose. I am getting a shorter bolt to eliminate the washers I had on there for testing. All the metal components of the bushing are clamped tightly together with the bolt screwed in (the top threaded nut assembly, the tapered inner sleeve, inside the rubber, and the large bottom plate.

 

[Ian C]

I had a similar issue with an aftermarket diff mount. The top and bottom plates of the mount became separated where the bolt enters.

 

[Cornishman]

I also tried to fit a new diff bush while I had mine apart, like yours it did not fit. So I replaced the old one which looked fine. Perhaps there are some incorrect parts out there. I have not chased up the supplier. PM me if you want to know the source.

Here are some rough photos that I took, one shows that they are a fingers width difference in depth.

Best wishes
C

 

[Luis A.]

Sven, did you ever figure out what was causing the noise? I'm installing a new diff mount bushing and I'm wondering about the outcome of yours.